The cornea and lens deflect a light ray entering the eye so that it falls exactly on the retina. The image formed there is upside down and reduced in size. Numerous nerve impulses send this image to the brain. These merge the images from the two eyes, thereby creating perspective and providing depth perception. If the images do not fall exactly on the retina, the brain cannot form a sharp image.
In a nearsighted person, the image falls in front of the retina. Everything in the immediate vicinity is in focus, but what is far away is blurry. Anyone who often squints to see something better or sits closer to the television is probably nearsighted.
In a farsighted person, the image falls behind the retina. Objects at a distance are in sharp focus, but objects close-by cannot be seen clearly. Having frequent headaches or having difficulty reading a book can be signs of farsightedness.
The treating doctor will discuss the treatment with you.
