Question about 40/40 on my eye exam?

Question

I went for my driver's test yesterday and they gave me an eye test before I went and did my road test. After I was done she gave me the paper back with my results of the eye test and it said 40/40, does anybody know what that means? Because I know I have very good vision but I thought that 20/20 was the best vision?

Answer 1

If it's not just a slip, 40/40 is exactly the same quality of vision as 20/20, except it specifies that the test was done at 40 ft instead of the usual 20.

Think of it as a fraction: 20 over 20 = 1, 40 over 40  =1.

20/20 is nothing like "the best vision" 20/15 =1.3, or even 20/12 are quite possible *for some individuals*.

20/20 is a *notional* normal vision for a healthy eye with no (or a corrected) refractive error.

There's only historical and mathematical reasons why it's ended up like that.  It's not a biologically determined, or absolute, point.

Answer 2

40/40 not the number for measure the visual acuity

the 20 feet or the 6 meter is the optical infinity for measure the visual acuity 20/20 is the good vision

Answer 3

Actually, there is no such thing as 40/40. I would worry about someone telling you about a problem with your vision if they give you that sort of information. Vision is based on 20 feet, so if you see 20/20 then you have normal vision.

See a real doctor for real answers, not the DMV.