How The Eye Sees
Vision is about light. Here are how some parts of the eye affect our vision.
All light must first pass through the cornea when it enters the eye.
Light rays then penetrate the lens. Muscles and ligaments change the shape of the lens to fine-tune the focus of light onto the retina, the light-sensing portion of the eye.
In a normal eye, the cornea and lens will refract light in perfect focus onto the retina. Numerous light-sensitive receptors in the retina, called rods and cones, give colour and contrast to our vision.
Most of the light rays are concentrated onto the fovea, a tiny area on the retina. The fovea is responsible for our central, sharpest vision. Light stimulates the nerve cells present there to send "signals" via the optic nerve to the brain where we perceive images.
The white, outermost layer of the eye, called the sclera, maintains the shape of the eye. The choroid supplies blood and nourishment to the tissues in the eye.