| The most encouraging fact about your eyes is | | | | pigment, and is largely a nutrient organ, providing |
| that the less effort you make to see the better | | | | nutritive liquid to the retina. Within the choroid is a |
| you can see. It is hard for people with imperfect | | | | 3rd coat, an extension of the optic nerve, a |
| sight to believe that perfect sight needs no | | | | delicate surface called the retina. This is an |
| effort; indeed, any effort to boost the sight | | | | exceedingly thin and highly advanced surface, in |
| makes it worse. | | | | which are the terminations of the nerve tendrils, |
| Curiously enough, we have always known that | | | | which are of two kinds: rods and cones. |
| before we can swim or dance, play tennis or golf, | | | | Click here to learn eye exercises. |
| or master a musical instrument, our muscles must | | | | Here form and color and pointy definition are |
| be relaxed. Acquiring that relaxation of the | | | | registered. Beyond this spot, cones and rods |
| muscles has often been the toughest part of | | | | mingle, but toward the periphery only rods are |
| learning any of these things, but without it all the | | | | found. These are delicate to dim light and thus are |
| other lessons are useless. It's a similar case with | | | | used for night seeing. |
| the eyes. | | | | About a tenth of an inch To the nasal side from |
| Click here to learn eye exercises. | | | | the center is the optic disc, the point of entrance |
| The eyeball itself is made of 3 distinct layers, or | | | | of the optic nerve, commonly called the blind spot. |
| coats. The outer part, which we know as the | | | | When light rays reach the outside of the retina, |
| white of the eye, but which is more properly | | | | the radiant energy goes through a process of |
| called the sclera, is a difficult, fibrous tissue, which | | | | chemical change, and this new form of energy is |
| starts where the cornea leaves off, and extends | | | | carried by the optic nerve into the visible centers |
| back to where it is pierced by the optic nerve. | | | | of the brain. |
| Four-fifths of the sclera is opaque; the leftover | | | | In myopia, or shortsighted vision, the rays of light |
| one-fifth is a translucent area immediately at the | | | | are thrown to a point in front of the retina. |
| front of the eye, called the cornea. | | | | Such is the wonder and complexity of our eyes. |
| Inside the sclera is a second coat, or lining, known | | | | Click here to discover how to do eye exercises. |
| as the choroid, consisting of blood vessels and | | | | |