Q re 'Better than normal' eyesight

Factual Questions
1

Some people have more acute vision than ‘normal’ – I know a man who has 20/10 vision, meaning he can make out at 20 feet what ‘average’ people can’t make out unless they’re only 10 feet away.

My question is, what gives them this better vision?

Do their eyes have better lenses/focusing ability, sort of a more powerful telescopic lens affect?

Or do the have have, well, ‘better’ rods and cones in their retina? Mayber smaller ones packed more densely, resulting in finer details being discernable?

Or something else?

2

I asked this same question some time ago on this Board. The consensus was that 20/20 is average (normal?), but not the best possible vision. However, an EMS guy told me that some people have more rods and cones that enable them to see better. My thought was 20/20 means that the focus point is on the retina, as it should be, and that if you can see better, something else must come into play. You can’t do better than having the focal point on the retina. I still think, therefore, (I am?) that the rods (and cones?) are the difference.

3

WAG: they have the opposite of people who are short-sighted. Since shortsightedness is corrected with a lense (glasses), I guess it’s a focusing problem - the lens in your eye can’t deform enough to focus on far things.

Hang on though, isn’t it normal to be able to focus at infinity? In which case they’d have to have igher resolution, or more rods/cones.

I’m not sure now.

4

Sorry, no. Not due to extra cones, or rods, etc. The theoretical best for visual acuity is 20/8, and this is based on the size of the cones themselves.

People with better than 20/20 vision are basically far-sighted; the eye is a bit too short for the configuration of their native lens.

QtM, MD

5

Meaning this guy is ‘Hawkeye’ now, but he’ll be the first whose arms are too short later on?

Every advantage has a counterbalancing drawback, I guess, sooner or later.

6

So it’s the size of the cones and not the focal point, as stated in a prior thread I started. Thanks for clearing that up, ** Qadgop the Mercotan**.

7

I had an interesting discussion with my eye doctor about this. Although I am dreadfully nearsighted, I can be corrected to slightly better than 20/20. This is essentially because my “circuitry” supports better vision even though my eyeball is mishapen. My wife, who was nearsighted, was corrected to somewhat better than 20/15 with Lasix. The surgeon got it pretty much spot on and she had the potential for very good vision. On the other hand, perfect surgery might leave other people with 20/25 or 20/30.

And, yes, my wife will probably get her reading glasses a year earlier now.