Lenses That Bend Light

Light that is reflected from objects all around us passes through the eye lens and forms images on the retina at the back of the eyeball. This activates the nerves leading to the brain, which develops the moving pictures so formed. But these images happen to be upside down or inverted! What a blessing for us that the Designer of the eye also instructed the brain on how to turn these images the right way up!

The inversion of images as they enter the eye occurs because our eye lens is convex, similar in size to an aspirin tablet. And this type of lens has the unusual feature of “twisting” light rays that pass through it to form an inverted image of the object originating the rays.

The Superlative Eye Lens

When you look at the “black hole” in your eye, you are really looking through the lens into the dark interior of the eyeball. The tiny lens is held in place behind the colored iris by ciliary muscles and follows the same principles of refraction that man has applied in artificial lenses. The brain, by converting nerve impulses transmitted to it from the retina into full color, three-dimensional moving pictures, gives us an exciting upright view of something larger than the image on the retina but always in optical proportion to our bodies. This is true whether it is a pea or a plate, a vase of lilac blooms or magnificent, snow-clad mountains.

For us to be able to look at a map on our knee one moment and, the next, to view scenery and mountains miles away indicates that the eye lens has been perfectly designed. Instantly it can focus sharply, automatically correcting aberrations that would be found in man-made lenses. How confusing it would be to have a distorted image constantly changing with every movement of the head, with multicolored fringes around each image!

The refractive and focusing agencies of the eye, the lens itself and the cornea (that curved transparent covering of the eye), truly proclaim the intelligent handiwork of the Creator. Even Charles Darwin admitted the absurdity of his natural selection theory when he considered the eye: “To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.”​—The Origin of Species, p. 190.

The Spectacle Lens

The eye lens is extremely flexible and can be bent, pulled out or elongated and squashed flatter. It is this ability in association with the refractive power of the cornea that permits quick, accurate focusing without distortion.