What is my vision when wearing glasses?

Question

I mean what do they aim for, average vision, 20/20, or better?

I presume there is some sort of standard.

I'm in England, if there's a difference.

Answer 1

They aim for 20/20. However, some people cannot be corrected to 20/20 for whatever reason and others easily correct to 20/15 or better.

Answer 2

It depends on the eye and how good the presciption is the goal is always at least 20/20 but it could be better or worse than 20/20.

Answer 3

They do aim for 20/20 (or 6/6 in Europe, I think, because of the metric system) because that is assumed to be average vision.

If your vision is easily correctable to 20/15 and that correction doesn't cause strain, they'll do that. The amount of correction they can achieve can vary between the two eyes as well; for example, in my right eye I can see 20/15 with glasses, and in my left eye it varies between 20/20 and 20/25--partly due to the degree of astigmatism in my left eye.

Answer 4

They want 20/20, if possible.

It's universal.

Answer 5

20/20 is obsolete in the UK and anwhere else that uses metric measurments: Europe, Asia... though it's still understood.

The 20 refers to the test distance, 20ft, and the metric equivalent is 6 metres, 20/20 = 6/6, 20/40 = 6/12

The normal aim in refraction is to get each eye to its best focus.  More lens power does not give more vision...

It's much more like tuning in a radio station.

Having found the "best spot", the vision that results is not set by the power of the glasses, but the quality of the lens / eye / retina / nerve / brain system as a whole.

If there's cataract, amblyopia or macular degeneration, for example, no Rx lens is going to produce 6/6. The principle acuity limit isn't in the focal length error.

Most healthy eyes, with appropriate correction if required, can achieve 6/6, many can do somewhat better, 6/5 or even 6/4 occasionally and 6/3 very rarely, but having 6/9 as best is normal for some people (but that would only be concluded when the possibility of problems had been considered, as in most cases 6/9 best acuity would mean something needed looking at.)

6/6, 20/20 is just a very rough shorthand for "pretty good vision".  It's not an ideal or a particular objective.  People vary too much.  6/6 is not a solid safe, good, benchmark.

Someone capable of 6/3 would not consider 6/6 "clear vision" at all, and they'd be right.

And someone with 6/6 could have such severe glare difficulties from early cataract that they needed surgery.

(Not theoretical: I've met both instances)