Can one pair of glasses do it all? You need bifocal lenses and you like to wear sunglasses. The only answer is Transition lenses. These are the lenses that change from clear to tinted when exposed to sunlight. Not just any light. Sunlight. Direct Sunlight. You can walk into a lighted room or store and the lenses will lighten to clear within a few minutes and back to sunglass density when you return to the direct sunlight. The density of the color in the lens will adjust depending on the intensity of the sunlight. The more direct daytime sun produces a dark sunglass tint while dawn or dusk-type conditions produce a much lighter yet comfortable density. Any prescription lens type can be made with this feature. Single vision, bifocal, trifocal, or progressives and in all materials as well like polycarbonate, hi-index, and standard plastic. Transitions in a brand are used by the lens manufacturers to produce their lenses with a photo-sensitive capability. Many of these lens manufacturers have their own photo-sensitive treatments which are very adequate at photo-reacting when exposed to sunlight. It is also true that these brands can be made at a lower cost which can cost you less or create more margin for the retailer. Our experience has been that the Transitions brand has always offered a more proficient photo reaction and a more neutral grey sunglass color. Even in the alternative brown color, the Transitions brand is better.
Here is where the Transitions lenses or any other brand of photo-sensitive lenses will not function as well as a separate pair of prescription sunglasses. Daytime driving. If you like to wear sunglass lenses while driving during the daytime hours your Transitions lenses with not stay tinted in the car unless you are driving a convertible. Remember that it is direct sunlight that darkens the lens and when you are driving you are “inside” your car. This can be a deal breaker if your primary need for sunglasses is daytime driving but remember, with Transitions lenses, you only have to switch glasses in the car and only during the daytime hours. All in all a great feature to consider for a pair of glasses you probably live in.