Subject: Most ODs simply prescribe for extreme sharpness of vision. This almost always means that a person with self-checked 20/20, will get a -3/4 diopter lens.
Item: I AGREE that we must have OBJECTIVE requirements that we MUST PASS. But that requirement is 20/40, not 20/15. This is why personal competence and self-checking are so important. I have yet to have an OD say, "... I am giving you a strong minus - because it will impress you. Be very careful, and keep it off your face, unless necessary..."
Since they do not warn me, I must take a greater deal of responsibility to self-check and obtain my own minus from Zennioptica for $9, if necessary. For the record, here are all the State requirements - for your interest.
http://lowvision.preventblindness.org/daily-living-2/state-vision-screening-and-standards-for-license-to-drive#PennsylvaniaFor those interested in improving their own Snellen (visual acuity), I suggest honoring these requirements, by checking yourself.
Obviously, if at 20/50, you will have to get a minus to drive a car. If reading the 20/25 line, you can avoid getting a minus lens. Use your own common-sense on this subject. Be wise, and be safe.
With 20/40 vision, you can avoid the minus almost all the time.
It is my belief, that if a very motivated person (with 20/40) actually took plus-prevention seriously, he could eventually get to the 20/25 to 20/20 range. But only the person himself will verify that result.
