Grid marks/dark spots after IPL treatment of entire face in less than 15 minutes. Will my skin tone even out? (Photo)

After laser treatments, it is common to have "grid" like marks on the face, or even areas that temporarily look "striped". As a provider, it is difficult to clearly see your skin and it's condition without seeing you in person. I will say, however that it is fairly common to have a grid-like pattern after getting a laser treatment. It is usually not permanent. After having laser treatments, it can take up to 2-3 weeks to fully heal. During that time you may have a striped or grid pattern, you may feel tender, you may have a grey-sh hue to your skin, and some areas may look like the skin is darker, often described as "peppering" or "coffee grounds". I do not know the kind of laser that was used on you, nor do I know the settings or your skin. At this juncture, I would try not to panic and let it heal. Sometimes applying Aquaphor, sunscreen with zinc, and perhaps Bacitracin can expedite the healing process and help to prevent complication. If after several weeks you still have the grid, go see your practitioner. Sometimes lasers will leave that look until after the entire series is finished as it can be difficult to get all of the skin treated in one treatment. 

Best to return to see your IPL doctor for treatment. In my practice I would start you on 4% to 8% hydroquinones ASAP... 

Those marks should resolve, but I'd recommend you see the physician who owns the office. I am sorry they treated you with a service they did not explain at all. That's poor office management. While I'd say you were definitely overtreated with the IPL, I don't think long-term damage is present that I can see. Still, see the physician asap for a possible prescription of hydroquinone. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."