Eye Anatomy: Structures at the Front of Your Eye

Structures at the Front of Your Eye

• Light from the TV travels through the air to reach several major structures in the front of the eye, including the cornea, iris, pupil, lens, and ciliary muscles.
• These structures work together to help us see and interpret light entering the eye.

The Cornea

• The cornea is the outermost layer of the eye, a transparent layer that covers the iris and pupil.
• It bends light as it enters the eye and is involved in sensing pain.
• The cornea has many nerves, making it very sensitive to scratches, which can be very painful.

The Iris and Pupil

• The iris is the structure that gives us our eye color and controls the amount of light reaching the back of the eye.
• The iris controls the amount of light entering the eye by changing the diameter of the pupil.
• The pupil is a hole in the middle of the iris that allows light to enter the eye.
• The pupil constricts in bright light and dilates in low light to let more light in.

The Lens and Ciliary Muscles

• The lens is a structure behind the iris that focuses light rays entering through the pupil to form an image at the back of the eye.
• The lens helps us see things near and far away through the process of accommodation.
• The ciliary muscles contract to shape the lens into a ball for focusing on close objects, and relax to shape it into a flat disk for focusing on far objects.
• Without a lens, we would only be able to see things at a very far distance.