health

In most cases, farsightedness occurs when the eyeball is shorter than normal.
For an object to appear clear, the light passing through the eye must
focus on the retina, a layer of photosensitive cells on the back of the
eye. The retina is like the film in a camera. It is where the image passing
through the eye is projected and then sent along the optic nerve to the
brain. In the brain, the image is developed into what we see. If the eyeball
is too short, the image that is projected onto the retina by close objects is
blurred, and the person is said to be farsighted.
People with farsightedness usually have the disorder from birth. It is
probably inherited from parents; however, just because a parent is farsighted
does not mean the child necessarily will develop the problem
too. Babies and younger children often are able to adapt to the problem.
Muscles around the eyeball can change its shape, making it longer and
allowing the image to be focused properly on the retina. As a child gets
older, however, the muscles cannot do as good a job changing the eyeball’s
shape, and images close up are out of focus.