Lower eyelid retraction, like lower lid ectropion, is caused by a compromised support system but also by the shrinkage of any of several tissue layers (skin, muscle, retractors). Lid retraction can occur naturually, with aging, with thryoid disease, or as a consequence of overdone transcutaneous lower blepharoplasty.
In the photo below, overdone horizontal and vertical shortening during blepharoplasty caused the lower lid to pull down below the cornea (eyelid retraction), exposing the white of the eye (scleral show).

Severe post-blepharoplasty
eyelid retraction
There is no one all-inclusive approach to the correction of lower eyelid retraction, and not all cases can be corrected. Repair of lower eyelid retraction after blepharoplasty is an advanced operation that must be individualized using techniques such as:
• support reinforcement (canthoplasty)
• grafting of an internal spacer (hard palate, etc.)
• skin grafting
• SOOF or midface lift, and/or
• augmentation of insufficient bony support below the eye