Dear Prevention minded friends,
If you are in an office, as an OD, in a dark room and you can detect even the slightest "error" (your machine might not be working correctly) you will over-prescribe the minus lens. Here is a conversation with a woman who "woke up" and checked her own Snellen - and has 20/20 vision. Clearly the OD's motivation to sell you an expensive minus lens - that you do not need - drives this excessive prescription habit. Tragically, if you start wearing a strong minus - it will screw up your distant vision -- and in my opinion, permanently. This is why I do not argue about, "un-doing" the effect of a minus lens on the normal eye.
Here is the report by Ms. Bronwyn:
Bronwyn> Hi Otis, I am very confused by the results from when my friend and I checked our visual acuity with and without our glasses. My results don't make any sense to me. I was able to read almost all of the 20/10 line outdoor with my glasses on. I can understand that and was pleased. It's the results without my glasses that have me perplexed. According to our testing, I read the 20/40, 20/30, 20/25, 20/20, and 20/15 lines perfectly. I was even able to guess a couple of the letters on the 20/13 line correctly. We must have been doing something wrong for me to get these results. Was it because we read the chart in the sunlight? I did get a massive migraine afterward from reading the chart without my glasses. I also got one on a day that I forgot to wear my glasses and left them at home. These were my first two migraines. I am going to go to a health fair on Saturday and I will ask them to check my vision with and without my glasses.
My Response:
Otis> to Bronwyn P Hi - Since you read the 20/20 line, with no glasses on - you are profoundly over-prescribed. In simple words - you are not myopic. Or, you are profoundly over-prescribed !! Do not bother the OD with this issue. You read your Snellen objectively. If you wished to be a pilot (read the 20/20 line) you would qualify. Always check yourself - and stop wearing glasses - you proved to yourself - you do not need.