Although there is certainly a “coolness factor” involved with choosing which sunglasses to wear, the real question we need to ask ourselves is:

Why SHOULD I wear sunglasses?

The answer to this question is simple: environmental protection and visual comfort.

Before discussing these points, let’s briefly review optics and the optical components of the eye. Light is measured in wavelengths that make up both the visible spectrum (which we see as various colors) and the non-visible spectrum (which contains Ultraviolet (UV) and Infrared (IR) light). When light rays enter the eye, they travel first through the cornea and then the lens, before finally focusing on the retina. Each of these three tissues is susceptible to deterioration over time from the potentially harmful effects of UV and, to a much lesser extent, IR wavelengths.

It has been well-documented that long-term exposure of the human eye to ultraviolet light contributes to the development of cataracts and retinal (macular) degeneration. For this reason, all good quality ophthalmic lenses, both clear and tinted, include a UV filter. It is worthwhile to note that the UV filter is actually clear, which means the darkness of a lens has no bearing on the ultraviolet blocking capability of that lens.

Read the full Story at Trifit360 by Jeff LaFerla, OD FAAO is a graduate of the Indiana University School of Optometry. He completed a residency in contact lenses at the University of Missouri-St. Louis. Dr. LaFerla resides in Weatherby Lake, Missouri with his wife and two sons. He completed the iron distance Redman Triathlon in September 2009 in Oklahoma City. Email Dr. LaFerla at