45. Your Eyes

Light goes through the pupil, the dark hole the center of your eye. The light becomes image on the retina, which converts these images nerve impulses. The brain reads these impulses and “” you what you are seeing. The image that retina receives is upside down, but the brain it to right-side up.

In an experiment years , a brave researcher wore special lenses that turned upside down. After stumbling around for awhile, he used to the lenses because his brain corrected images. To conclude his experiment, he stopped wearing lenses. After awhile, his brain returned his vision normal.

People with vision problems are usually near-sighted far-sighted. Near-sighted people see clearly only objects that near; far-sighted people see clearly only objects that far away. Both groups of people need corrective (glasses or contacts).

People whose near and far is good have “20/20” vision. People with poor might have 20/40 vision (or worse). That is, person with good vision can see an object 40 feet away as clearly as a person poor vision can see the object from 20 away. No matter how good your vision is you are young, you will need reading glasses you get old.

Your pupils get bigger as light source gets dimmer, but your pupils also bigger if you see something (like a delicious ) that interests you. “Your eyes are bigger than stomach” is an expression parents use when a fills his plate with more food than he eat.