Alberta Grade 8 Science Light and Optical Systems Practice Test 2026 – Complete Study Resource

The cornea is the clear tissue at the front of the eye. It serves as the eye’s outer focusing surface, bending light as it first enters the eye to help form a sharp image on the retina. It provides most of the eye’s refractive power, while also protecting the eye with its smooth, transparent surface maintained by tears. The iris is the colored part that regulates light entry, the retina is the light-detecting layer at the back, and the lens behind the pupil provides additional focusing and can change shape for near or far vision.