Which part forms the transparent outer window of the eye?

Which part forms the transparent outer window of the eye?

• A. Iris
• B. Retina
• C. Cornea
• D. Sclera

Answer: (C)

Light first passes into the eye through the clear front surface, the cornea, which forms the transparent outer window. Its main job is to allow light to enter and to bend (refract) it a bit to begin focusing the image on the back of the eye. The cornea stays transparent because it has a highly organized structure and no blood vessels, and it receives nutrients from tears and the fluid inside the eye. The other parts shown have different roles and appearances: the iris is the colored ring that controls how much light enters by adjusting the pupil; the retina is the light-sensitive layer at the back that processes visual information; the sclera is the tough, white outer coating that protects the eye.

Light first passes into the eye through the clear front surface, the cornea, which forms the transparent outer window. Its main job is to allow light to enter and to bend (refract) it a bit to begin focusing the image on the back of the eye. The cornea stays transparent because it has a highly organized structure and no blood vessels, and it receives nutrients from tears and the fluid inside the eye.

The other parts shown have different roles and appearances: the iris is the colored ring that controls how much light enters by adjusting the pupil; the retina is the light-sensitive layer at the back that processes visual information; the sclera is the tough, white outer coating that protects the eye.