Some Past Experiences with Cataracts/Surgery

View previous topic View next topic Go down

Some Past Experiences with Cataracts/Surgery

Post by xmastershooter on 11/12/2017, 7:00 am

The topic of cataracts never drew this much attention 10 years ago on our Bullseye site, so I guess there are more and more older shooters now.  First, I'm an Optometrist and not an Ophthalmologist.  I don't do surgery.   That means I see the progression of my patients' cataracts before surgery and their results after surgery.  I see some good results and some not so good.  I don't tell them they have 20/20 vision when they don't.

Shooters and everyone else should consider cataract surgery when their quality of life have been affected by subnormal vision and not "gut it out."  When one waits until the nuclear sclerosis of their lens becomes very opaque, the surgeon will have a more difficult time removing the cataract and complications may arise.  Undoubtedly, such a patient would be lucky to be under anesthesia and not hear the surgeon curse during surgery.  Smile Just kidding!

One must make their own decision as to which Intraocular implant would be best.  Members of this forum have posted good results with the different choices, monofocal, multifocal, and accommodative.  I do agree that the monofocal IOL will consistently provide better and stable vision, important for shooters. 

A couple of patients come to mind who opted for the multifocal IOL. One, from a local club didn't recalled which type of IOL he received.  With my best efforts, his responses kept changing as I showed him various lenses for his eyeglass prescription for both far and near, super sharp one second and blurred a minute later.  He had the multifocal IOL.  He was never quite happy with any prescription.  Another patient paid extra for the multifocal IOL and expected no need for eyeglasses afterwards, but was extremely bitter when she needed a distant and near prescription and was not correctable to 20/20 vision.  Of course, there were many others who were very happy with their mutifocal IOL's.

For those who have monofocal IOL's, we can "always" come to a final endpoint for their best prescription, and if their eyes were healthy, they had 20/20.

Surgeons are human and computers are very important but not infallible.  Results cannot be guaranteed.  Measurements for the axial length of the eye from the front of the cornea to the fovea are critical for a good result.  If the measurement is off by 1/3 of a mm, the patient will need a 1.00 dioptor lens to correct the vision.  One member of the forum wrote to me that his post-op prescription was +1.50 D in one eye.  Visual acuity wise, that would translate to about 20/80 to 20/100 uncorrected vision.

The IOL's come in 0.50 D power increments but recall that our eyeglass prescriptions come in 0.25 D steps.  Although small, there a chance that the post-op vision could be slightly off.  As to the terms "stronger" or "weaker" IOL powers, there may be some slight confusion.  A stronger IOL than what the computer recommends means that the new focal point would be in front of the fovea (of the retina) and thereby result in a myopic situation.  This is not a bad result.  The opposite, when the new focal point is behind the fovea, we then have far-sighted situation, not desirable.

When one is slightly myopic after surgery, one can still see relatively well far and fairly well at near, depending on the exact numbers.  Since most of our daily tasks require near vision to some degree, one can do well most of the time without the need for eyeglasses.  Your eyecare professional can simulate these various scenarios simply by demonstrating with trial lenses during the pre-op exam.

On a different topic best discussed later, there are fine differences when I fine-tune a shooters prescription for their best vision.

xmastershooter

Posts : 118
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by BE Mike on 11/12/2017, 7:47 am

I recently had an eye exam and the optometrist said that my cataracts still weren't bad enough for surgery. One thing I've noticed over the years and more so lately is that when shooting with iron sights I tend to group to the far left. This is mostly when shooting double action, two-handed. I very recently had to adjust my S&W model 19-3 revolver's rear sight so far to the right that it is hanging slightly off the right side. This also happens with Glocks, Sig P320, etc. I have been wondering if this is a result of my vision. I wear prescription shooting glasses that make the front sight clear. Care to comment?
avatar
BE Mike

Posts : 1390
Join date : 2011-07-29
Location : Indiana

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by james r chapman on 11/12/2017, 7:55 am

Mike, try shooting with the off eye and see where your impact is.
Just for comparison
avatar
james r chapman

Posts : 2117
Join date : 2012-01-31
Age : 68
Location : HELL, Michigan

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by xmastershooter on 11/12/2017, 8:22 am

Let me see if I got this correct.   You write that the shots group to the left with the revolver, but you've moved the rear sight to the right?

xmastershooter

Posts : 118
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by Virgil Kane on 11/12/2017, 8:29 am

I had cataract surgery on my right eye about 10 years ago because of a childhood injury to that eye.  Now when I cover my left eye I see a ghost image of what I'm looking at or if I look at a straight black line on a white piece of paper I see a "kink" in that straight line. When I read very small print letters disappear until I shift my eye to read the next word.  When I look at the black bullseye of a target with iron sights  I see that ghost image of the bullseye, front sight and rear sight, it makes the bullseye look like a figure 8 and the sights almost unusable with any precision.  Does the same when I shoot both eyes open or use an opaque shade on my left eye.
Doctor told me that it is from an astigmatism but for 55 years of my life I never had that problem until I had the surgery. After seeing several different doctors for this problem I was told by the doctor that did the surgery that I would have to live with it and I shouldn't want to be an enigma and be poked and prodded.  

I know that my surgery is the exception and not the rule but after getting no answers and not much help from the doctors I saw I would be skeptical of any promises made for this surgery.

Guess I could learn to shoot left handed but being old and stubborn I don't know if I want to start the learning process over at my age.  

Not expecting answers just relating my story.

YMMV

Virgil

Virgil Kane

Posts : 461
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by xmastershooter on 11/12/2017, 9:31 am

There are 4 components that affect vision:
1. Cornea
2. Lens/capsule
3. Retina
4. Brain

Complications from cataract surgery may involve the cornea and lens capsule.  If these are normal, the retina may be checked with OCT.   A brain lesion is a long shot since your complaints happened after cataract surgery.  A brain scan will eliminate that as a contributing factor.

I saw a patient complaining of a recent onset blur, scotoma (lost of vision area) in his lower right visual field.  After a comprehensive eye exam, I suspected some type of brain lesion involvement and referred him to a specialist.  He had recently saw an Ophthalmologist a couple of days before with this same complaint and was told he had dry eyes after doing only a rudimentary exam.  The clinic took him more seriously after my referral letter with my report.

xmastershooter

Posts : 118
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by BE Mike on 11/12/2017, 10:24 am

xmastershooter wrote:Let me see if I got this correct.   You write that the shots group to the left with the revolver, but you've moved the rear sight to the right?
Yes, I adjust the rear sight the way I want my group to move. It also happens with semi-auto pistols. I don't seem to have this happen with the air pistol. With the air pistol, I wear Knoblochs with a corrective lens and an adjustable iris shutter. On the off eye I have a blank eye cover.
avatar
BE Mike

Posts : 1390
Join date : 2011-07-29
Location : Indiana

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by Virgil Kane on 11/12/2017, 6:19 pm

Best explanation I got was from a rep for an implant company.  He theorized that the replacement lens must have  gotten creased when it was put in and therefore the ghost images and bent lines.

My wife might agree with you that I have some brain problems,  lol!  , but I believe as you seem to that I would of had that problem long before and not immediately after the lens replacement.  I have seen cornea and retina specialist for this problem and none have an answer.  My lens replacement remains an enigma after almost a year of seeing different eye doctors.  Funny thing is I have a friend on another shooting team that has the same problem as I do.  Like brothers from another mother.


A question that I never got answered was this.  Within about a week or so of having this lens replacement I had what the doctor called a secondary cataract. He used a laser to remove it.  I always wondered if that laser treatment could have done something to the implant in some way.

All is well though and I have no such problems using a red dot ( not as noticeable anyway) but irons are still a mess to deal with.

Thank you for your answers in the previous post.

Virgil

Virgil Kane

Posts : 461
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by xmastershooter on 11/12/2017, 7:07 pm

Virgil, Since your doctor mentioned astigmatism, does your problem go away while wearing your correction eyeglasses?  I wouldn't think so, and if it doesn't then astigmatism is not the problem.

You've most likely had this checked already, but click onto this link for the Amsler Grid test and follow the directions.  Let's check it again.

  http://amslergrid.org/AmslerGrid.pdf

The "secondary cataract" commonly occurs after surgery, and is known as Posterior Capsular Opacity.  After the cataract is removed, the lens capsule remains intact but the back portion can become cloudy. The YAG laser will easily open a hole during an in-office procedure.  I don't this would be the likely source of your problem.

xmastershooter

Posts : 118
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by xmastershooter on 11/12/2017, 7:29 pm

BE Mike wrote:Yes, I adjust the rear sight the way I want my group to move.
Of course your answer was correct to my test question! Evil or Very Mad

There are different types of cataracts with numerous appearances but I can't think of how this can affect your grouping.  Two glaring items from your posts come to mind.  You stated that the problem occurs "mostly" shooting double action revolver, which means this is not a problem with single action.  Also, the errant grouping doesn't occur with air pistol.  Could it be that with the heavier trigger pull, some bad habits developed?  An easy way to tell would be to shoot off sandbags to check the groupings.  I've found that very exacting trigger control would always be needed to shot off sandbags to get good results.  Shots out of the 10 ring may not be from questionable load, bullet, or inaccurate pistol.  Please let us know your sandbag results.  Thanks, take care.

xmastershooter

Posts : 118
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by Virgil Kane on 11/13/2017, 7:14 am

xmastershooter wrote:Virgil, Since your doctor mentioned astigmatism, does your problem go away while wearing your correction eyeglasses?  I wouldn't think so, and if it doesn't then astigmatism is not the problem.



No it does not go away. As a matter of fact when I wear polycarbonate glasses it seems to make things worse than wearing regular glass or plastic lenses for some reason.  I had done  the Amsler Grid before but will try it again.  Don't know if it makes any difference but this problem gets worse when the lights are dim or reading street signs with car headlights or street lights.  The brighter the sunshine the less noticeable it is. 

  When looking at this realistically I would have to say that the doctor did his job correctly.  After all I had this done at an early age (mid 50's) because of the need for excellent eye sight in both eyes for my profession.  I only had the right eye done and to this day there is no reason to have the other (left) eye done.  Most patients that have this procedure  are much older and they would gladly trade (or even notice) the ghost images for the ability to see clearly again. 

With many professions and the shooting sports that we all enjoy we tend to put extreme emphasis on your eye sight.  Not that the expectations are wrong but in the scheme of things having any ability to see somewhat clearly is much better than the other options.

Virgil Kane

Posts : 461
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by BE Mike on 11/13/2017, 7:48 am

xmastershooter wrote:
BE Mike wrote:Yes, I adjust the rear sight the way I want my group to move.
Of course your answer was correct to my test question! Evil or Very Mad

There are different types of cataracts with numerous appearances but I can't think of how this can affect your grouping.  Two glaring items from your posts come to mind.  You stated that the problem occurs "mostly" shooting double action revolver, which means this is not a problem with single action.  Also, the errant grouping doesn't occur with air pistol.  Could it be that with the heavier trigger pull, some bad habits developed?  An easy way to tell would be to shoot off sandbags to check the groupings.  I've found that very exacting trigger control would always be needed to shot off sandbags to get good results.  Shots out of the 10 ring may not be from questionable load, bullet, or inaccurate pistol.  Please let us know your sandbag results.  Thanks, take care.
This grouping to the left also occurs with Glocks and Sig P320. The group is usually a decent group about 6" left of the center of the target. As a former master bullseye shooter and PPC shooter, as well as, having shot double action revolvers for decades (shooting double action) combined with the fact that the groups are good, I am hesitant to think that the problem is trigger control. Of course I don't rule that out. I'll try shooting with the weak eye and bench resting.
avatar
BE Mike

Posts : 1390
Join date : 2011-07-29
Location : Indiana

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by Mike M. on 11/13/2017, 7:22 pm

xmastershooter wrote:One must make their own decision as to which Intraocular implant would be best.  Members of this forum have posted good results with the different choices, monofocal, multifocal, and accommodative.  I do agree that the monofocal IOL will consistently provide better and stable vision, important for shooters. 
simply by demonstrating with trial lenses during the pre-op exam.
This is what has me reconsidering.  Right now, I was planning on getting an accommodative lens, then use glasses to correct for astigmatism.  Which I have a slight amount in the left eye (which needs to be done first), more in the right eye (the shooting eye, it's enough to give me a headache if I read without glasses more than an hour or two).  The other option would be to go with a toric IOL to correct the astigmatism, then use glasses to focus for near distances.  Which would you recommend?

Mike M.

Posts : 15
Join date : 2011-07-18
Location : Deep Southern Maryland

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by xmastershooter on 11/14/2017, 12:42 am

Mike M., I hope this helps................

I read the recent postings "Cataract Surgery Options for Shooters" with much interest and it seems all were happy with their various decisions.  If one is seeing 20/40 to 20/100 or worse because of the cloudy cataract and is also bothered with glare and dimmer vision, then seeing 20/20 once again through whichever IOL used would be a blessing, even with the additional use of eyeglasses.

Count me into the cub of needing cataract surgery in the near future as my left shooting eye has developed the cataract and is slowly progressing.  My decision at this time would be the toric monofocal IOL for my left eye.  I would most likely opt for full distance focus or slightly closer (0.25 to 0.75 myopia) because most of our daily routine visual tasks does not include driving.  With this way, I would be able to see more things at a closer range and still see distance relatively well.  I'm not adverse to wearing eyeglasses to get the fine focus, and finally, I will be able to have lenses that are not thick.

Of interest, astigmatism changes throughout our lives.  Astigmatism generally refers to the cornea not being spherical, but there is also astigmatism on the lens.  The more common type is called with-the-rule astigmatism, where the vertical axis is steeper than the horizontal axis. This corneal toricity tends to flatten throughout our lives.  In college, my astigmatism was around -3.50 diopter and now -1.50 diopter, which is a significant difference.  I'm not aware of any studies of vision changes after cataract surgery, but more likely than not, there will be refractive changes.

Those who have undergone Lasik need to discuss with the surgeon of the concern of false readings during the pre-op exam which influences the IOL power.  One of my shooting patients who was excited with his cataract operation ended up with -4.00 D post-op eyeglass prescription because of the false reading.

Additionally, it is very important to inform your surgeon if you are taking Flomax or equivalent for reduced urinary flow due to enlarged prostate.  This can cause Intraoperative Floppy Iris Syndrome (IFIS) in which the iris muscles are affected and can lead to complications.  Typically your doctors will recommend stopping this drug for a couple weeks prior to surgery.  Very important!

xmastershooter

Posts : 118
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by mikemyers on 11/14/2017, 3:14 am

We would all be better off if we referred to monofocal lenses as "precision" and multi-focal lenses as "convenient".    

With the first, you get the most precise vision at one distance, but have to wear eyeglasses for other distances.  

With the second, you get a compromise that works over a range of distances.  

I don't like calling multi-focal lenses "premium".  That word makes them sound better than the others, which is not true, although they do have "premium" pricing.  Chances are that with either, you will still need eyeglasses.

Personally, I would skip all the "premium" stuff and go with the standard mono-focal IOL, although if toric correction was needed, I would definitely get that.  Then your glasses don't need to correct for the astigmatism.

-----------------------------

For several reasons, cataract surgery is not an exact science.  Everything has a "tolerance", meaning the IOL can end up under-correcting, or over-correcting.  In addition, the IOL might end up in a slightly different position than anticipated.  Given the choice, I would ask for an IOL power to make me slightly near-sighted.  That way, something, at some distance, will be clear without glasses.  If your vision ends up such that the eye is focusing behind your retina, nothing, anyplace in your field of view, will be perfectly sharp, meaning you will always need to wear glasses.

(Besides, thanks to what photographers refer to as "depth of field", it's likely that things before and beyond the point of focus will appear sharp.  If your IOL is designed to give you perfect vision "at infinity", all the potential benefit of depth of field beyond that point of focus (infinity) is wasted.)
avatar
mikemyers

Posts : 401
Join date : 2016-07-26
Age : 73
Location : South Florida, and India

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by mikemyers on 11/14/2017, 3:29 am

Most of my thinking about cataracts came from here:
http://aravind.org/content/aravindmediapdffiles/journalcasestudies/HowMcDonald.pdf

The surgeon who replaced the cataract in my right eye holds the record of doing over 150 surgeries in one day.  That's why doctors from all over the world come here to learn.

Because of the "McDonalds" concept, a huge number of people from remote villages are given their sight back - many for no charge.
avatar
mikemyers

Posts : 401
Join date : 2016-07-26
Age : 73
Location : South Florida, and India

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by BE Mike on 11/14/2017, 7:30 am

mikemyers wrote:Most of my thinking about cataracts came from here:
http://aravind.org/content/aravindmediapdffiles/journalcasestudies/HowMcDonald.pdf

The surgeon who replaced the cataract in my right eye holds the record of doing over 150 surgeries in one day.  That's why doctors from all over the world come here to learn.

Because of the "McDonalds" concept, a huge number of people from remote villages are given their sight back - many for no charge.
Could it be that doctors "from all over the world" go there to learn because there is much less chance of a law suit?


Last edited by BE Mike on 11/14/2017, 2:29 pm; edited 1 time in total
avatar
BE Mike

Posts : 1390
Join date : 2011-07-29
Location : Indiana

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by mikemyers on 11/14/2017, 10:58 am

If they don't know enough, they start on "practice eyes" in the "wet lab".  From what I've seen though, almost all the doctors from Europe and the USA are already very talented, and get sent to Aravind to share and learn new techniques.

Below - training session during a "wet lab session" during AGES-25, with doctors coming to the conference literally from all over the world to learn and discuss the latest about glaucoma.  The fellow at the left in this photo is Alan Robin, who is world famous.  I had a lot of enjoyable discussions with him, when we were away from the official parts of the program.  If anyone is interested:  https://www.glaucoma.org/treatment/interview-with-alan-l-robin-md-improving-glaucoma-care.php



Several people here have entered information about how they are dealing with Glaucoma.  Getting good advice is the same as anywhere else, go to a place you trust with good people.  I know the basics of how they treat glaucoma, but the most important thing I have learned is the importance of getting eye examinations by a qualified person often enough that something like glaucoma can be treated before the damage becomes irreplaceable.  I wish every one of those people had access to Aravind, but the round trip flight is already $2,000 plus other expenses.  The doctors at Aravind have constantly told me that the eye care in the USA can be just as good (added by me - if you find the right people).

(Which is so sad to read here that someone had a serious eye problem, and his eye-care professional diagnosed it as dry-eye.  Sad.)
avatar
mikemyers

Posts : 401
Join date : 2016-07-26
Age : 73
Location : South Florida, and India

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by BE Mike on 11/14/2017, 2:35 pm

xmastershooter wrote:
BE Mike wrote:Yes, I adjust the rear sight the way I want my group to move.
Of course your answer was correct to my test question! Evil or Very Mad

There are different types of cataracts with numerous appearances but I can't think of how this can affect your grouping.  Two glaring items from your posts come to mind.  You stated that the problem occurs "mostly" shooting double action revolver, which means this is not a problem with single action.  Also, the errant grouping doesn't occur with air pistol.  Could it be that with the heavier trigger pull, some bad habits developed?  An easy way to tell would be to shoot off sandbags to check the groupings.  I've found that very exacting trigger control would always be needed to shot off sandbags to get good results.  Shots out of the 10 ring may not be from questionable load, bullet, or inaccurate pistol.  Please let us know your sandbag results.  Thanks, take care.
I think I've narrowed my problem down to the shooting glasses I've been using to shoot iron sights. The prescription lenses on my Randolph glasses are made to focus on my front sight and they do that well. They are however, very thick lenses. I tried shooting air pistol with them and my group was left! I went back to the Knoblochs and the group was centered. Looks like I need to go back to the drawing board and get a new pair of prescription shooting glasses (not as thick) for shooting iron sights.
avatar
BE Mike

Posts : 1390
Join date : 2011-07-29
Location : Indiana

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by xmastershooter on 11/14/2017, 3:35 pm

I will be adding a couple of new topics to my "Bullseye Shooters' Guide For the Eyecare Professional" soon.  This will include Monocular vs. Binocular testing and the need to consider depth of field when testing for the shooting prescription.

xmastershooter

Posts : 118
Join date : 2011-06-10

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by mikemyers on 11/14/2017, 9:57 pm

BE Mike wrote:...... Looks like I need to go back to the drawing board and get a new pair of prescription shooting glasses (not as thick) for shooting iron sights.
When you did this last time, what did you take with you to get the refraction done?  Your gun?   A tape measure, to tell the person how far away to put the eye testing page for near reading?

I'm asking because I tried the tape measure method last year, and the results weren't so good.  Then I made the gizmo I posted the photo of, and the eye testing was effortless (although it thoroughly confused the person doing the refraction).  Once she caught onto what I wanted, it all went smoothly.

Maybe they can use a different material to reduce the thickness.  You can read about "index of refraction" before your next visit.  I know about "glass", "plastic", and "polycarbonate".  There are likely even more choices.
avatar
mikemyers

Posts : 401
Join date : 2016-07-26
Age : 73
Location : South Florida, and India

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by BE Mike on 11/15/2017, 8:14 am

mikemyers wrote:
BE Mike wrote:...... Looks like I need to go back to the drawing board and get a new pair of prescription shooting glasses (not as thick) for shooting iron sights.
When you did this last time, what did you take with you to get the refraction done?  Your gun?   A tape measure, to tell the person how far away to put the eye testing page for near reading?

I'm asking because I tried the tape measure method last year, and the results weren't so good.  Then I made the gizmo I posted the photo of, and the eye testing was effortless (although it thoroughly confused the person doing the refraction).  Once she caught onto what I wanted, it all went smoothly.

Maybe they can use a different material to reduce the thickness.  You can read about "index of refraction" before your next visit.  I know about "glass", "plastic", and "polycarbonate".  There are likely even more choices.
I took a contraption made of wood with a handle and front sight. They told me I could bring my pistol next time as long as I told them in advance and had it in a case.
avatar
BE Mike

Posts : 1390
Join date : 2011-07-29
Location : Indiana

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by Chris Miceli on 11/15/2017, 8:30 am

BE Mike wrote:
mikemyers wrote:
BE Mike wrote:...... Looks like I need to go back to the drawing board and get a new pair of prescription shooting glasses (not as thick) for shooting iron sights.
When you did this last time, what did you take with you to get the refraction done?  Your gun?   A tape measure, to tell the person how far away to put the eye testing page for near reading?

I'm asking because I tried the tape measure method last year, and the results weren't so good.  Then I made the gizmo I posted the photo of, and the eye testing was effortless (although it thoroughly confused the person doing the refraction).  Once she caught onto what I wanted, it all went smoothly.

Maybe they can use a different material to reduce the thickness.  You can read about "index of refraction" before your next visit.  I know about "glass", "plastic", and "polycarbonate".  There are likely even more choices.
I took a contraption made of wood with a handle and front sight. They told me I could bring my pistol next time as long as I told them in advance and had it in a case.
i got an appointment this weekend, the doc just had me book the last appointment of the day... so i can bring my airpistol.


Last edited by Chris Miceli on 11/15/2017, 9:56 am; edited 1 time in total
avatar
Chris Miceli

Posts : 1570
Join date : 2015-10-27
Location : Haymarket, VA

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by mikemyers on 11/15/2017, 9:02 am

Whatever you bring, the distance from your eye to the front sight needs to be correct for the way you hold the gun.  For me, with my 1911, that is 24" two-handed, and 30" one-handed.  One size does not fit all.

If you tape a business card to the front sight, so it has more to look at, that will make the vision test easier.  I made the gizmo like I did, so I could bring it with me for the refraction, and then to verify that the lenses worked as intended.  Everything was so easy.

Depending on the lighting in the room, you may or may not see the sights on the air pistol that well.  With the business card there is no doubt, and as they ask "is this better", you'll know the answer instantly.  If you're not sure, bring both the mock-up gun, and the air gun.

If you shoot both iron sights and red dot sights, you will want to get a second pair of glasses set to be good at 50 yards.  That makes it easy.


Not sure if anyone else would like this, but I did all the above only for my shooting eye.  For my other eye I set them to the distance to my bench top, for working on the guns, reading, adjusting the sights, etc.  All of them should be polycarbonate.  IMHO.
avatar
mikemyers

Posts : 401
Join date : 2016-07-26
Age : 73
Location : South Florida, and India

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by jmdavis on 11/15/2017, 9:10 am

One reason the knoblochs may work better is that they may be parallel rather than at an angle to the eye. I am mainly applying my knowledge of photo lenses, but there are some guys who have been tweaking their lens for more than 50 years. Many of them came from photo backgrounds. 

Another issue is that while you want a clear front sight, you also need to see the bull, it is possible to be in a situation where you have a perfect front sight but the bull has fuzzed to the point of being background (ask me how I know). Admittedly that issue is primarily with rifle more than pistol. But I have experimented with shooting eye lenses for several years looking for the right one. Eventually I asked my eye doc what he used for irons, and that answer was better than what I was getting based on the theory. 

Right now I need +1 for normal distance with my shooting eye. I have tried, +1.5, +1.75, +2, and +2.25 for irons with the 22 and Service Pistol. With good light (i.e. Perry) and no cover, I like the +2.0. In dimmer light, I like the +2.25. With the airgun indoors in good range light, I wind up using the +1.75 or the +2.0. 

I will often test a particular lens by having a cheap set of glasses made at Zenni optical (i.e. China). They work good for that purpose and my dot glasses are a pair of theirs. 

Custom Sight Picture has a kit that you can rent to check things for your self.  An optometrist who is also a Master Pistol shooter developed it. They also have a tint kit, that can make a difference. http://www.customsightpicture.com

Shooting Sight has a kit that you can buy (-1.5 to +1.5 in .25 increments) and also a less expensive kit on a paddle that goes from +.25-+1.25. https://shootingsight.com

 I have the paddle and also a +.125 lens for tweaking. It should be noted that getting a +.125 scrip generally means that there will be no anti-reflective coating on the lens. Maybe Xmastershooter can address that, but that is my understanding. 

Regardless of any of that, or perhaps in addition to all of it. The shooter needs a wide enough rear sight that the can see white space on either side of the front space. Nygord recommended a 1:2:1 ration or a 1:1:1 ratio. 

http://www.cincinnatirevolverclub.net/nygordsnotes/sights.htm

In concluding, I would recommend that people not just start buying lenses. Even though you can get them for $16-$40 each, some research will help you to not wind up with a collection of 15 or 20 lenses.  Talk to your optometrist. Read XMastershooter's writings on the subject from Ed Hall's page. Check out a variety of online resources, then make decisions.
avatar
jmdavis

Posts : 1110
Join date : 2012-03-23
Location : Virginia

Back to top Go down

Re: Some Past Experiences with Cataracts/Surgery

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum