Sight+Vocabulary

__**iris**__ - the colored part of your eye, it opens and closes to control the amount of light let in. __**pupil**__ - the opening that the light goes through __**lens**__ - the clear part that focuses the light and lets you see near and far __**cornea**__ - a tough, clear covering that covers and protects the iris and the pupil __**sclera**__ - the white part of your eye that covers all the eye except the front. __**retina**__ - a network of nerves on the back of your eye, the nerves absorb light waves __**optic nerve**__ - this takes the vision signals to the brain __**rods**__ - special cells in your eye that see shades of gray and let you see in the dark __**cones**__ - special cells in your eye that let you see colors

__**Other facts:**__ The eye is the organ we see with (duh, right?) The eye is shaped like a ball. The **bones** in the head, along with the **eyelashes**, **eyebrows**, and **eyelids**, protect the eye. An **ophthalmologist** is an eye doctor that examines eyes, performs surgery and treats eye injuries and diseases. An **optometrist** makes and fits glasses.
 * Tears** wash away things that are stuck in your eye.
 * Nearsightedness** is when you can clearly see things that are close to your eyes, but not things that are far away.
 * Farsightedness** is when you can see things far away clearly, but not things close up.
 * Astigmatism** is when your lenses, corneas, or both are too flat. Things look wavy and twisted.
 * Blindness** is when you've lost most or of all of your sight.
 * Presbyopia** is a condition when your lens can't focus, making if hard to see things up close.
 * Color blindness** is when you can see certain colors. (Check this out to see how people with color blindness see)