There are benefits and drawbacks to both photochromic lenses and prescription sunglasses. It's important to weigh the pros and cons of each to determine which option is better for you.
Photochromic lenses like [Transitions](/prescription-lens/transitions) are light-sensitive. So, when you're indoors (or outside at night), the lenses are clear and look just like regular glasses. When exposed to UV rays, the lenses automatically darken to accommodate your environment. This offers a convenient alternative to switching between separate pairs of sunglasses and eyeglasses.
However, some people prefer prescription sunglasses over photochromic lenses because they are fully darkened all the time. This is especially handy when driving because car windshields often filter some UV rays and may prevent photochromic lenses from darkening completely in the car.