The side of the eye may tilt downwards and sometimes people wish for this to be corrected. Options would include cathopexy (repositioning the tendon that supports the eyelid into a more superior position) or even implants or bony surgery.I would recommend an evaluation with a board certified plastic surgeon to determine the best course of action for you.
Downward slant of the lateral canthus, antimongoloid slant, needs a full examination. Can be corrected by a canthoplasty procedure.