The realm of human knowledge will probably always be incomplete, but we learn new things about the world every day. Concerning the degeneration of health, the mantras of “it just happens” or “it’s genetic” seem to rule our consciousness. Never, it seems, is there a bona fide reason for grandma’s Alzheimer’s, your arthritis, or my crappy vision. It is that last one that bothers me the most, because doctors have never been able to tell me why I’m myopic (nearsighted). They are quick to be able to fix it, though, with glasses, contacts, and surgery. As is so common, we are great at treating disease, but not so great at stopping the onset.
Why, then, does myopia happen? I never got a clear answer, but as with so many things, “nothing in biology makes sense except in the light of evolution,” though some would disagree. Not being able to see your prey or something trying to kill you isn’t a positive trait. According to research on modern hunter-gatherers, between 0 and 3 percent of them are myopic. Contrast that with the US and the rest of the industrialized world.
According to the British newspaper the Guardian,
Rates [of myopia] are lower [in Britain] – between 30 and 50% – but ophthalmologists agree that myopia is on the rise. “We can’t be sure of the numbers,” says Winfried Amoaku, consultant ophthalmologist at Queen’s Medical Centre in Nottingham, “but the increase in myopia, especially in eastern countries, really is quite rampant.”
Loren Cordain, author of The Paleo Diet seems to have a reason, that nicely correlates with the increasing encroachment of junk food. Myopia is a result of–you guessed it–consumption of neolithic foods. The onset of myopia may likely be a consequence of chronically high insulin levels. Having bad vision isn’t something that would naturally happen evolutionarily. Chronically high insulin, leads to insulin resistance, which tends to lead to a host of bad effects, like heart disease, acne, and obesity. One other consequence of hyperinsulinemia is an increase in insulin-like growth factor, which may result in increased growth of the eyes, which leads to myopia. Check out professor Cordain’s flow chart on page 12 of this link for more information, or check out his paperon the subject.
Like most events, bad vision is multi-causal, so reading and computers most likely have some effect. It is an interesting hypothesis and I’ll be thinking about it when I have kids of my own. I’d rather they not be visually impaired, like me!
If there are any ophthalmologists or doctors out there that would like to comment, feel free.
–Nick
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