Blepharoplasty can be both a functional or cosmetic surgical proceure intended to reshape the upper eyelid or lower eyelid by the removal and/or repositioning of excess tissue as well as by reinforcement of surrounding muscles and tendons. When an advanced amount of upper eyelid skin is present, the skin may hang over the eyelashes and cause a loss of peripheral vision. The outer and upper parts of the visual field are most commonly affected and the condition may cause difficulty with activities such as driving or reading. In this circumstance, upper eyelid blepharoplasty is performed to improve peripheral vision. Patients with a less severe amount of excess skin may have a similar procedure performed for cosmetic reasons. Lower eyelid blepharoplasty is almost always done for cosmetic reasons, to improve puffy lower eyelid "bags" and reduce the wrinkling of skin.