I wrote a book about eye health called The Eye Diet . It kept me from needing to switch to the nightmare of trifocals. But almost no one has read it. So I decided to make a short, simple summary for a busy world. The book has all the research, but here are a few of the things I found. One, eye sight is not a one way downhill slide . We lose most of our eyesight during our teens, and then during our perimenopausal years (sorry guys, our hormones change too). Otherwise, sight tends to be pretty constant. Two, ten hours a day of screen time does permanently affect sight . We are seeing a pandemic of extreme nearsightedness that promises to enormously increase legal blindness across the globe. And three, the good news, there are simple things you can do to help your eyesight . Get outside . Use natural light to read by. Get your children outside. We do not have artificial light that can match the sun. If you are having trouble reading, practice using the sunlight.