The treatment itself is kind of intense but not painful. The pulse of the laser light is so bright you can actually 'see' it when your eyes are covered and closed. It sort of makes you jerk because it is so sudden and bright even though you know it is coming. I would equate it to the same discomfort as laser hair removal on the underarms. My skin was stingy and red for about 3 hours after but by my 3rd treatment I was almost maxed out on power and had almost no discomfort after the treatment.
Overall, it was worth it to keep some of the age spots from creeping up on me. I have also noticed some softening of fine lines around the eyes. Definately give it a try if you want the softening of the sunspots and if your medspa is running a special on it (like mine was!)