Operation Can Give Patients ‘HD’ Vision?

[Exavior]

You've got it backwards there. The vision acuity measurement is the other way around. It's measured as "Nominal / Actual"

What she has is probably 20/17, as she can see at 17 feet what most people should see at 20.

Anything better than 20/20 is just "better than average/normal." I get my checkups done to include visual exams relating to head/neurological issues I have to keep an eye on for for progression of symptoms... 20/10 in my left, 20/12 in my right. Considering my mum is nearsighted and my father is farsighted, I got lucky. Either way, I could have had really fucked vision.

Sorry you are correct, I did type that backwards.

No, you've got it wrong: http://en.wikipedia.org/wiki/Visual_acuity

20/17 means *BETTER* vision than 20/20. It's measured in Actual / Average. So 20/17 means that person can see at 20 feet what most see in 17 feet.

So if you really are 20/10, congrats - you have vision that is roughly two times better than average.

Actually he was right, I was wrong. I wanted to say she had better than 20/20 vision but the way I typed it would be worse.

I see where your coming from though, but I think its mostly used because people can relate to the word, and quickly understand what is implied in the use of it.

But that isn't any different than normal vision, by your definition there my normal glasses give me HD vision as they make things clearer. It is nothing but a buzz word.

 

[Headfoot]

Some of this must already be available in regular glasses, because after I got my most recent pair my right eye went to 20/10 and my left eye to 20/15 .

 

[Nanan]

...

Vision via that system is usually broken into segments of 5 thus you see 20/20, 20/15, and whatnot quite often. Other systems go much more accurate but use a standard of deviation system of 0 +/-.

 

[kllrnohj]

Sorry you are correct, I did type that backwards.



Actually he was right, I was wrong. I wanted to say she had better than 20/20 vision but the way I typed it would be worse.



But that isn't any different than normal vision, by your definition there my normal glasses give me HD vision as they make things clearer. It is nothing but a buzz word.

The denominator is the distance from which an 'average' person would be able to distinguish —the distance at which their separation angle is 1 arc minute. The metric equivalent is 6/6 vision where the distance is 6 meters. Twenty feet is essentially infinity from an optical perspective (the difference in optical power required to focus at 20 feet versus infinity is only 0.164 diopters). For that reason, 20/20 vision can be considered nominal performance for human distance vision; 20/40 vision can be considered half that acuity for distance vision and 20/10 vision would be twice normal acuity.

20/17 is better than average.