functional and cosmetic are two types of eyelid.
1-Functional eyelid surgery: A functional eyelid removes the excess skin that obscures your field of vision. Other functional issues which require eyelid surgery include discomfort from strained muscles which struggle to lift sagging eyelid skin and eyelid skin irritation from excess skin numbing during eyelid movement.
2-Cosmetic eyelid surgery: A cosmetic procedure can be performed on either the upper or lower eyelid, or on both. Depending on the type of lower eyelid blepharoplasty, either excess skin in the lower eyelid is removed or a redistribution or removal of excess fat is performed. As we age, fat pockets become more prominent, muscles weaken, and eyelid skin stretches. These factors may detract from your facial appearance leaving you with an older or worn-out appearance.
Details of the eyelid surgery:
There are three distinctly different types of eyelid surgery, and the surgery you'll require can be different depending on the shape of your eyes and other health conditions. One of these three types will be recommended by your specialist:
A:Upper Eyelid Surgery: This type of blepharoplasty is used mainly to improve loss of your vision and appearance of the eye due to aging or genetics. As the name implies, it's focused on the upper eyelid. This type of surgery can restore the function of the eye or provide a more rounded, open appearance.
B:Lower Eyelid Surgery: Eyelid procedure is based around the lower lid and eyes, focusing on the removal of wrinkles in the skin, correction of baggy eyes or improving appearance.
C:Double Eyelid Surgery: In a double eyelid surgery, a crease is made in the upper eyelid, creating a wider, larger-looking eye. This is the method that's gained so much popularity in East Asia, and the one most often referenced in relation to blepharoplasty as a whole.