Take one of your own digital photographs and enlarge it. Then enlarge it again and again. Eventually, you will see the pixel squares it is made of. That is the same idea as the little light sensors we have on the backs of our eyes.
Take one of your own digital photographs and enlarge it. Then enlarge it again and again. Eventually, you will see the pixel squares it is made of. That is the same idea as the little light sensors we have on the backs of our eyes.