Actually, when we sell photochromatic lens, it's a case of customer asking for it. The option is there as more and more people these days want it for convenience sake. I normally tell people if they want to use in bright conditions, they should get another pair of rx sunglasses. This is not because I can sell more frames but for practical reasons. Let's look at them.
1) Everyone knows that transitions don't turn dark behind a car's windscreen, so they have no added value when driving.
2) They never get dark enough, compared to a true sun lens, even under the brightest conditions and full UV.
3) Contrary to popular belief, the truth is that even clear lenses with the prerequisite coatings also provide 100%UV, the difference is the amount of light transmission, not UV transmission (99.7% light transmission for clear lenses vs 30% to 99% for photochromatic lens). The photochromatic lenses actually are about 99.5% UV protection because a certain amount must be let in to allow the lenses to tint.
4) Absolute Cost - It gets exponentially higher when customers request for higher index and other features.
5) Relative cost - Prescription tinted lenses with UV coating are not that expensive in comparison and can be tinted to how dark or light the customer wants. If the additional amount cost for photochromatic lenses are put to use elsewhere, the customer can get a thinner, even aspherical lens that are stronger or an even more superior coating.
6) Even though improvements have been made from a few generations ago, photochromatic properties are designed to last the life of the prescription only. What will happen is that after 3 years or so, the speed in which the lens darkens and clears is reduced and in some cases, there is a permanent grey cast to the lens.
7) Their optimum operating temperature is between 15-28 degrees celsius. Not only are said lenses sensitive to UV, they are mucho sensitive to ambient temperature as well. Those who live in seasonal climates will experience that in the summer, the lens are clearer and change much slower while they are darker/ greyish during winter. What this means is that the hotter it is, the worse it will work. Based on Singapore and especially middle eastern climates which can reach 40 degrees, you are actually shortchanged when you buy transitions in these regions.
8) Some customers actually mention that transitions type lenses when activated makes them look "dishonest" and "pervertic". I am not one to judge but there are feedback as such.
Anyone who sells photochromatic lenses and tells you otherwise is either hardselling or he has already a large margin in place on top of what the lab charges.
