How the Eye Works Anatomy of the Eye
Light enters the eye through the clear outer dome, the cornea, and goes through the pupil. The lens is just through the pupil: it transmits and focuses images on the retina, which is like film in a camera. The macula is the central receptor site of the retina and provides our sharp vision for tasks such as reading and driving. The retina sends the images via the optic nerve to the brain for visual processing.
Why We Don't See - Focusing Problems
Near-sighted or myopia The focusing elements of the eye are too strong and light comes to focusing front of the retina. The eye is "too long or too strong.
Far-sighted or hyperopia
The focus of the eye is too weak and the image of what we should see is not yet focused when it hits the retina. The eye is "too weak or too short."
The eye is not perfectly round and the image of what we see is twisted or distorted.
Occurs with all eyes: normal vision, myopia, hyperopia, and astigmatism. It is not a shape problem but is an internal aging problem. The eye muscles cannot change the shape of the lens to focus on near objects. Nearvision declines and reading glasses or bifocals become necessary.