The ingenuity of man has been at work hundreds of years to discover some other method of adapting an optical instrument to long and short range, but without success.

Now, the Former of the eye knew the properties of light and the properties of lenses before the first eye was made; he knew the mode of adjusting them for any distance, from the thousands of millions of miles between the eye and the star, to the half-inch distance of the mote in the sunbeam; and he had not only availed himself of both the principles which opticians discovered, but has executed his work with an infinite perfection which bungling men may admire, but can never imitate.

The sclerotic coat of the eye, and the choroid which lies next it are full of muscles which, by their contraction, both press back the crystalline lens nearer the retina, and also flatten it; the vitreous humor, in which the crystalline lens lies, a fine, transparent humor, about as thick as the white of an egg, giving way behind it, and also slightly altering its form and power of refraction to suit the case.

Thus, that which the astronomer, or the microscopist, performs by a tedious process, and then very imperfectly, we perform perfectly, easily, instantly, and almost involuntarily, with that perfect compound microscope and telescope invented by the Former of the human eye.

Surely, in giving us an instrument so admirably fitted for observing the lofty grandeur of the heavens and the lowlier beauties of the earth, he meant to allure us to the discovery of the perfections of the great Designer and Former of all these wondrous works.
But there is another contrivance in the eye, adapted to lead us further to the consideration of the extent of the knowledge of its power.