Eyesight refers to an individual's ability to see or their visual acuity. It is determined by factors such as the clarity of the lens in the eye, the sensitivity of the retina and the efficiency of the nerve connections between the eyes and brain. Good eyesight means being able to clearly distinguish shapes, colors, and distances while poor eyesight can result from conditions like nearsightedness (myopia), farsightedness (hyperopia) or astigmatism which affects the way light is focused onto the retina.