Why does human vision have no lens distortion like most cameras do?

Actually, the human eye can create distortion in ways similar to a camera. In an emmetropic eye (one with no need for glasses), the optical image is what we think of as normal. But in the case of myopia (nearsightedness) for example, the concave glasses (especially in high myopia cases) create a "minification" effect where the image looks smaller and farther away than normal. Thick convex glasses (to treat a hyperopic -farsighted - eye) do just the opposite: the image through them is larger and seems closer than normal. Aging of the natural lens creates flare and halos around lights at night.

In general, the human eye is a remarkable optical "device" with built-in correction factors for spherical aberration, coma, and other optical aberrations. But when the eye deviates from normal, there can indeed be all the same distortions that photographers must deal with…and more.

Written by J. Trevor Woodhams M.D. - Chief of Surgery, Woodhams Eye Clinic