See The Light!

Is it the fault of your parents that you’re shortsighted? Yes and no, as VERNE MAREE finds out, while also suggesting a few paths to better eyesight.

- Verne Maree

Poor eyesight runs in families, but the causation is not as direct as you might think. The child of two near-sighted parents has a one-in-three chance of being nearsighted too. If neither parent is near-sighted, the probability is a mere one in 40.

It’s understandable, then, that my 20-20 vision parents were surprised when the school nurse sent a note to say that their nine-year-old daughter was as blind as a bat and urgently needed some nice, thick spectacles. Each year, those lenses got thicker. Later on, my younger sister developed myopia too – but nowhere near as bad as mine.

Most eye problems are caused by the eyeball being too long or too short, causing the cornea or lens to refract light too far in front of or behind the retina. Too short, and you’re myopic, meaning short-sighted. Too long, and you’re farsighted – able to make out distant road signs, but not the ingredient list on a cereal box. (The upside? You’ll be able to enjoy those toxic Fruit Loops in blissful ignorance.)

Nature or Nurture?

As usual, it’s a bit of both. Poor eyesight can have just as much or more to do with lifestyle as it does with genes – and the fascinating new science of epigenetics sheds new light on the nature vs nurture debate. Epigenetics, of course, concerns itself with the ways in which environmental factors influence gene expression. Being an avid cricket player, cross-country runner or kite-flyer would tend to switch off your myopia genes, for example, while an obsession with Lego or gaming would tend to switch them on.

If I’d spent more time playing outside and less time curled up indoors with my nose in a book, I may not have ended up incapable of reading the number on a bus… and possibly even learnt how to throw a ball.