What is the window of the eye?

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

Answer: (C)

The window of the eye is the cornea. Light entering the eye first passes through this transparent, dome-shaped front surface, which acts as the entryway for vision. The cornea is avascular and highly transparent, minimizing light loss, and its curved shape provides most of the eye’s refractive power—about two-thirds of the eye’s total focusing ability. After passing through the cornea, light continues through the aqueous humor to the lens and on to the retina, where vision is formed. The iris is the colored part that regulates how much light enters by changing pupil size, the retina is the light-detecting layer at the back, and the sclera is the tough, protective outer layer. That combination makes the cornea the eye’s window.