DRUGSTORE READERS
There are many misconceptions about the "magnifiers" you may find in your local drugstore and even grocery store. This will not be an all out assault on such devices, although I'm tempted, but rather an informative abstract that I hope you will find useful. These mass-produced, quickly-assembled optical devices are actually prescription lenses that you may buy without a prescription. The instructions for selecting the proper power are as follows: "try me on; can you read this?; OK, buy me." Well, that may be a bit dramatic but that does essentially describe the procedure. No one will tell you that these "cheaters" will ruin your eyes, including myself, but there are a few things to consider before you take that $10-$20 plunge.
The first thing to consider is the possibility that your blurred near vision is the result of a medical problem that requires more investigation than trying on a few cheaters. Macular degeneration, central serous retinopathy, optic neuritis, diabetes, and several other conditions can simulate a need for reading glasses. Obviously, these are circumstances that demand a thorough eye examination. Secondly, these cheaters were made for the masses and therefore ASSUME that your two eyes are exactly the same, which is rare. Thirdly, these cheaters ASSUME that you have no astigmatism, and nearly 60% of the population does. Fourthly, these cheaters ASSUME that your eyes are over 65 millimeters apart when you read, but that only accounts for about 10% of you. Quite a few assumptions, don't you think?
We did our own study a while back and found a wide range of optical center readings for drugstore readers; i.e., that point in each lens that should sit right in front of your pupil when you read. Most men have a near "pd", or pupillary distance, of 60 millimeters and most women have a pd of 56. The optical centers of the cheaters we checked averaged over 65 millimeters, and the range was from 62 to 77! If you have a near pd of say, 58, and you spring for a pair of cheaters that is set for 76, you're in for a few headaches and an unnecessary amount of eyestrain. That amount of difference creates a significant "prismatic effect" that forces your eyes to turn in excessively and can result in blurred vision, a pulling of the eyes, and general fatigue.
Of course none of these symptoms will destroy your eyesight. It just seems to me that your eyes deserve better correction. They have served you well for many years, and this is not the best payback. Even more outrageous is when I hear from a patient that their last eye doctor told them to "just go buy some readers from the drugstore, that's all you need"! I think that is a disservice. There are better ways to save a buck than to impart your vision to this advice.
I think many eyecare practitioners may be timid in suggesting a good quality reading prescription if the patient's requirements are simple, maybe in fear of sounding self-serving. The person best served by a suggestion to acquire a good quality reading lens is the PATIENT!
I would sum up my opinion of drugstore readers in this fashion: If you only need an occasional aid to read the stock quotes, or find a number in a phone book, or thread a needle, or read a medicine bottle, then a ten-dollar cheater will probably do the trick. If, however, you work at a desk most of your day, spend a lot of hours at a computer, or just like to read, then invest in a top quality, corrected curve reading prescription that is measured and made for YOU specifically, and purchase your glasses from a reputable optical retailer. Your eyes will be beholden.