Photo-Facial, as the term sounds, is a technology that uses light for the treatment of skin. It is mostly used for lifting skin collagen, this in turn treats some skin conditions like brown spots, acne, skin redness, large pores, wrinkles and ruptured capillaries.
There are basically 2 ways for photo facial. One is LED (light emitting diode) and the other is IPL (Intense pulsed light).
Both technologies are very much different from each other, so it is important to know which one is best for you. Mostly LED is used in case of Acne, redness and bacterial skin problems and IPL is used in case of wrinkles, large pores, broken capillaries etc.
After all this information, I know you are also concerned about its side effects. This technology because based on light, target just the affected area, leaving surrounding tissues intact. However some redness may occur for a while.