Upper blepharoplasty incisions, when properly constructed, should blend into the preexisting eyelid crease and become invisible rapidly during the postoperative period. The lateral extent of the incision is exposed to the sunlight, and to the public, and needs to be cared for to produce optimum results. By far the most common result is that this incision becomes invisible (or visible only with a 10x magnifying mirror!) without a few months.
Proper care of the incision includes avoiding UV light. A silicone scar treatment is also quite helpful. The best way that I have found to do this is to use Biocorneum, a silicone scar treatment with UV protection built into it, twice a day. (This product is available in our offices for the same retail price as listed on Amazon.com). Below is a photo of a typical incision one month after surgery, in a patient without any makeup on.