Medical eye surgery is carried out to treat a condition that affects your vision or eye health. Examples include cataract surgery, glaucoma procedures, or surgery for retinal problems. These operations are considered necessary to protect or improve your eyesight and are often recommended by your eye specialist.
Cosmetic eye surgery, on the other hand, is performed to enhance the appearance of the eyes rather than to correct a medical problem. For example, eyelid surgery (blepharoplasty) to reduce drooping lids or remove under-eye bags is usually cosmetic unless the drooping skin is obstructing vision.
In short, medical eye surgery focuses on preserving or restoring sight, while cosmetic eye surgery is aimed at appearance and aesthetics.