Final answer:
Crystallins are the proteins that constitute over 90% of lens cells and are essential for the lens's transparency, allowing it to focus light onto the retina in conjunction with the cornea.
Step-by-step explanation:
More than 90% of the proteins in the lens cells are crystallins. These proteins are crucial for maintaining the transparency of the lens, which allows the lens to function alongside the cornea to focus light onto the retina. The cornea provides about two-thirds of the eye's focusing power, mainly because the speed of light changes significantly when it moves from air into the cornea. The lens offers the rest of the power necessary to adjust the focus and form a clear image on the retina. This image formation is critical for us to perceive the world around us correctly.
The eye's anatomy includes the sclera, cornea, lens, retina with the fovea, iris, and optic nerve. Through the pupil, light first passes through the cornea, then the lens, which can change shape thanks to attached muscles, to focus light appropriately, whether the objects are near or far. Eventually, it is cast on the retina, where the light-sensing cells, rods and cones, convert the light into nerve impulses, which are sent to the brain for interpretation as images. Quite remarkably, although images formed on the retina are inverted, the brain automatically corrects this, so we perceive them as upright.