For How Long Do I Have to Use a Sunscreen on my Upper Eyelid Surgery Scars?

Of course it is a good idea to apply sunscreen to any sunexposed area on a daily basis.  Scars can very rarely develop darkness or hyperpigmentation so I tell patients to be very careful about sunexposure and apply sunscreen to the scars at least for the first year.   Some redness to a scar 7 weeks after surgery is normal and it will usually fade by 3 months. 

Sunscreen is always a good idea (so is selling you convertible if your have one).  What your surgeon was concerned about was that your upper eyelid scars would hyperpigment after the surgery.  This is not generally something that we see.  If you have a history of hyperpigmentation, then the concern is more legitimate.  Persistent redness in a young scar can be improved with laser treatment  and you might discuss this with your surgeon.