There is a fundamental difference between age-related eyelid laxity and age-related ptosis, which is often confused with “ptosis”. We would like to introduce you to these two diseases. Age-related eyelid laxity: As we age, most older people develop eyelid skin laxity, wrinkles, septum laxity, orbital fat loss, and a “swollen eye” appearance. Mild skin laxity can cause double lids to disappear, sometimes giving the eye a triangular shape (commonly known as a triangle eye), while severe lid skin laxity can obscure most of the lid fissure, seriously affecting the visual field. Not only does this affect appearance, but it also causes serious inconvenience to life. Age-related ptosis: Age-related ptosis is a condition in which the upper eyelid muscles in some older adults are undersupplied with blood as they age, and the muscle fibers tend to atrophy and decrease in strength. The difference between these two conditions is very simple: if the upper lid margin is in a normal position 2mm above the pupil after lifting the loose skin, then the condition is considered senile ptosis, and if the upper lid margin is 2mm below the upper pupil margin or even obscures the pupil after lifting the loose skin, then the condition is considered senile ptosis. Treatment for both requires surgery, but the surgical options are not quite the same. For age-related ptosis, only the loose skin is removed to create a double eyelid, whereas for age-related ptosis, the levator muscle needs to be shortened to strengthen the levator muscle and thus lift the eyelid.