Are photochromic lenses good as computer glasses?
Photochromic lenses, which are transparent when worn indoors but darken when exposed to sunlight, have the added benefit of filtering blue light.
Computer glasses can make looking at a monitor more comfortable. These glasses typically have an intermediate prescription that helps you focus more easily at computer distance (about 20 to 40 inches). Some computer glasses have a blue light filter that may improve overall viewing comfort. So, depending on the prescription of your lenses, photochromic lenses may work well as computer glasses.
What are photochromic lenses made of?
Photochromic lenses are made of molecules composed of trace amounts of silver chloride (the same chemical compounds used to develop film). When this silver chloride is exposed to ultraviolet light, the molecules become silver metal, allowing the lenses to absorb visible light and turn darker in the process.
Unlike film exposure, photochromic lenses are also made with copper chloride, which strips the silver of its chloride electron. This allows the lenses to return to their original, non-absorbing state in the absence of ultraviolet light.
More modern photochromic lenses often contain organic molecules called naphthopyrans instead of silver chloride. Naphthopyrans change their molecular structure when ultraviolet light strikes them, making the lenses darken.
The difference between photochromic and Transitions lenses
The difference between photochromic lenses and Transitions lenses is that Transitions is a brand of photochromic lenses — one of several brands.
Photochromic lenses are also often referred to as transition lenses (lowercase t), hence the understandable confusion.
Let's take a closer look at the differences:
Photochromic lenses
Traditional photochromic lenses are made of plastic, glass or polycarbonate and change from transparent lenses to darker lenses when exposed to sunlight.
There are several terms used to describe photochromic lenses, including light-adaptive, light intelligent, variable tint and transition lenses.
Photochromic lenses are available in virtually all lens materials and in a variety of tints made for general-purpose lenses as well as contact lenses. Some sunglasses manufacturers even make tinted lenses that go from dark to darker shades rather than from clear to dark.
Transitions lenses
Transitions lenses are the most popular brand of photochromic eyeglass lenses sold in the United States. So some eye care practitioners even use the term "transition lenses" interchangeably with photochromic lenses (much like cotton swabs are almost universally known as Q-tips).
Transitions Gen 8 lenses, introduced in the U.S. in 2019, are the fastest light-adaptive Transitions lenses available.
So, are photochromic lenses good for computer use?
Photochromic lenses are versatile --- they function as glasses and sunglasses in one pair of spectacles. In addition to blocking ultraviolet (UV) rays, they have the added benefit of filtering blue light and reducing glare. It is just fine to wear your photochromic lenses at the computer if the prescription helps you focus clearly on your monitor.
