What is the typical treatment cycle for facial blemishes?

I have been spending a bit more time outdoors recently, and I am stressed because the brown spots around my cheekbones and under my eyes have become much darker than before. Even if I cover them thoroughly with concealer, they show through over time, making the skin look dull. So, I am seriously considering visiting a dermatologist to get laser treatment to remove the pigmentation. However, I have heard that this kind of treatment isn't a one-time fix but requires consistent sessions. Generally, when starting facial blemish treatment, how often should I schedule visits to avoid putting strain on my skin? I am worried that if I have to go once a week, it will be difficult to find the time while working. Also, I have heard that I need to be extra strict with sun protection during the treatment; I would like to know about aftercare tips or approximate schedules from those who have actually experienced this procedure.