Transition lenses are a type of photochromic material used in eyeglasses. Like other photochromic lenses, transitions change colour in response to light, darkening in bright sunlight and lightening indoors. These glasses allow users to use one pair of glasses all the time instead of having to switch back and forth from sunglasses to normal spectacles. But their disadvantages may mean they are not the best choice for certain wearers.
Transition lenses always keep a slight tint, even in lowlight conditions. According to JKounnas Optometrists, however, the tint is not pronounced enough to be a problem, even at night. If you have poor night vision or are frequently in dimly lit conditions, you may prefer the slightly higher light output of clear lenses.
Transition lenses do not change right away. When you go from a light location to a dark one or vice versa, it can take two to three minutes for the lenses to fully change. For casual day-to-day wear, this is not a problem since lighting conditions usually change slowly. But for biking at night or doing some other activity where you need to see clearly in rapidly changing lighting, transition lenses may not be the best choice.
Transition lenses don't respond to visible light. Instead, they react to changes in ultraviolet (UV) light. If you are outside, they work well to protect your eyes in UV-saturated sunlight. Car windows, however, block most of the UV light. As a result, your progressive lenses will not work in your car. In some cases, this may be an advantage, since the glasses won't darken unpredictably in response to headlights.