Burris Fastfire III

I bought Burris Fastfire III 3 MOA Dot, is it normal that I don't see a perfect round red dot but fuzzy? I am astigmatic but wearing glasses I see a perfect round dot on my Ultra Dot Four ..

I had exactly the same experience with FF3 and Vortex Venom. "Flare" or "Comet Tail" rather than a clear round dot. I have some Astigmatism.
Using an Eyepal aperture helped, but I see a much cleaner dot in the tube sights.
I've now sold all of the micro reflex sights and have Ultradot 1" tube 4moa on all competition guns.
I've recently bought a SIG Romeo 5 micro tube sight with 2moa dot and am experimenting. Too soon to make a judgement. But clearly better for me than an FF3 or a VV.
I don't know the technical details, but my practical experience is clear, if you have even slight astigmatism tube sights are better than micro reflex sights.

I find a larger dot is more round.  I also find turning it dim makes it more round.  I have an 8 min FF III on one gun.  All the way dim it is perfect indoors.   

I was told to make the dot so dim you can see through it.  This works except the Burris  only has 3 settings.   

My 2 newest guns have a Trijicon SRO.  My first one has a 2.5? Min dot.  The second one had a 5 min.   I prefer the 5.   

David

I use the next-to-lowest intensity on my FF3 and it gives me a decent dot.  Without my corrective lenses it appears "starry".

Bigtrout wrote:I use the next-to-lowest intensity on my FF3 and it gives me a decent dot.  Without my corrective lenses it appears "starry".

I use the lowest intensity and have no issues. Perhaps I am just used to it. Also, I don’t wear corrective lens.

My experience seems to be similar to others.

20/13 vision left eye and 20/15 vision with very slight astigmatism in the right eye.

Bigger dots in tubes look the same between both eyes.

Small dots in reflex sights are very slightly starry for the right eye only.

I can imagine that higher degrees of astigmatism will make this condition more pronounced.