by John Walker
Nearsighted people (those with myopia) like myself often share a disheartening experience with glasses. I've been nearsighted since I was born, but it wasn't diagnosed until I was in the third grade and complained I couldn't read stuff on the blackboard. My parents took me to the eye doctor who diagnosed me (I paraphrase) as “blind as a bat beyond arm's length” and prescribed coke-bottle lenses in robust black frames as the solution. Suddenly I could see all kinds of stuff I'd missed before. From the standpoint of 1950s ophthalmology, this was a miracle.
The first glasses prescription for myopia usually puts one on a treadmill where every couple of years you visit the eye doctor, get the tropicamide zap in the eyeballs, and walk out, squinting and bleary-eyed, with a prescription for ever-stronger glasses which require a week or so of adaptation, with the customary headaches. Repeat over lifetime, unless you discover what follows.
In January of 2000, after an incident involving a cat, a tree, a roof, a ladder, a pair of glasses, paws, claws, and Einstein's theory of general relativity, a tale which is so implausible that were I to relate it here you'd never believe it, I found myself at an optometrist's office to get new glasses. Since I had, five years earlier, reached the age where accommodation (focussing by the eye's lens) had become seriously constrained, I decided to order both “driving” glasses, corrected for focus at infinity, with a progressive grind where looking through the bottom of the lens was corrected for reading, as well as dedicated “reading” glasses, which were in focus with the eye's lens accommodation muscles at repose at a distance of around 40 cm.
Here is my eyeglass prescription from an examination on January 6th, 2000. This prescription is expressed in “minus-cylinder notation”, which is the usual convention for optometrists in Switzerland and most other countries.
When I received these glasses, I found them precisely as expected—with the driving glasses, objects at a distance were in focus, and if I looked through the bottom, I could read text near at hand. With the reading glasses, computer screens and books were in perfect focus without any strain, although objects at a distance were blurry, but not so much that I didn't know what they were.
Myopia is not just a condition of physical optics: it also has behavioural implications. A wise optometrist in Mill Valley, California, who I visited in 1991 shortly before I left the United States, remarked that he was required by California law to prescribe correction to 20/20 vision, although he said that for most myopes, who due to their early lives, spent most of their time looking at books or computer screens, such a correction created eye strain which caused us to require ever-stronger prescriptions. While this might be good for optometrists, it was far from optimal for the patients. He said, “I'd like to correct you guys to 20/40, but the law says I have to correct you to 20/20.” (Note that 20/40 vision is adequate to pass a driving test in California or anywhere else. Requiring 20/20 correction by optometrists is another example of utopianism.)
Once I got these glasses, I found I spent almost all of my time wearing the “reading” glasses. I'm a myope nerd—I spend almost all my life looking at a screen or page, and if stuff at a distance is blurry, well, I grew up accustomed to that. When I drive or I'm taking a walk, I use the corrected-at-infinity glasses, but that's on the order of 8 hours a week.
I hear you asking, “Where is the interesting stuff you promised?” Patience—here it is: conventional wisdom is that throughout the lives of myopes, our prescriptions only stay the same or get stronger. Myopia appears to be a progressive condition, and if you're born with it, you'll be wearing ever-stronger glasses throughout your life (although the rate of change may decrease as you age).
What I'm here to tell you, from a sample size of one, is that this may not need to be the case. I didn't really think about the advice of the Mill Valley optometrist when I opted to wear the reading glasses almost all of the time, and I didn't think about the possible consequences until around eight years later when I began to perceive that the correction of both my reading and driving glasses was too strong: I found myself moving them down my nose (the myope's focussing rack) in order to look at objects which were in focus when I started to wear the glasses.
In November of 2010, motivated not by a perceived need for change of correction (my nose is long enough to apply several dioptres of adjustment), but rather accretion of icky scratches on the lenses which were beyond being polished out, I went and had my eyes examined again (by the same people). The results were much as I expected, but startling from the standpoint of the expectation that myopia always gets worse. Here is my prescription from November, 12th, 2010, almost 11 years later.
I had always heard that as one aged, the rate at which one's myopia increased would reduce and converge to zero. But I had never heard any suggestion that any intervention could actually reduce one's myopia. And yet, here it is, evidence from an eye examination which is both confirmed by my own experience in the years before that my previous correction was too strong, and an independent examination by an M.D. ophthalmologist who verified the correction prescribed by the optometrist and found nothing amiss in either of my eyes.
What does this mean? If you're a myope and, as the Mill Valley optometrist inferred, you spend most of your life looking at things up close: books and computer screens, you might consider getting reading glasses corrected for that distance and wear them most of the time. You'll need glasses corrected for infinity for driving, wildlife and landscape photography, hunting, and viewing cinema, but if you're like me, that will average out to on the order of an hour a day. If your experience is anything like mine, you may discover that ditching 20/20 correction at infinity in favour of 20/20 correction at 40 cm will not only halt the progression of your myopia but, slowly, begin to roll it back.
If you're contemplating cataract surgery, with implantation of a fixed-focus lens, you might want to consider whether you wish to be corrected to infinity or for reading distance. If you've been a myope all your life, and you spend most of your time reading a book or looking at a screen, seriously consider asking to be corrected to focus at that range rather than infinity. Most people who never raise this issue with their eye surgeon are corrected to 20/20 at infinity, which is fine for driving, but requires reading glasses for reading books or computer work. If you spend more time with books or on the Web than at the wheel, you may wish to opt for a 20/70 correction at infinity which lets you spend most of your time without glasses. (If you have incipient symptoms of cataracts, I'd suggest you try zeaxanthin and astaxanthin: they work slowly and subtly, but they have completely reversed the development of cataracts for me within a year after I started taking them.)
As I noted in the title, this is an anecdotal report based upon the experience of a single individual. I do not remotely claim that my own experience is applicable to others: I have changed many other things in my life during the period documented here, and it's always possible one or another of them may be responsible for the changes I report. But if I really believed that, I wouldn't have published this. I think there is persuasive evidence that not straining one's eyes to focus on objects close at hand reduces and may even reverse the progression of myopia.
by John Walker