I often receive inquiries from parents about when to operate on their child’s ptosis. So, what is ptosis? Ptosis is the partial or total drooping of the upper eyelid due to the incomplete or loss of function of the levator muscle and the Müller smooth muscle. In mild cases, the pupil is partially covered, or in severe cases, the entire pupil is covered, which is not only aesthetically displeasing and affects vision, but can also cause severe amblyopia in congenital cases. If the upper eyelid does not cover the pupil or partially cover the pupil and does not affect the establishment of visual function, i.e., if it does not affect vision, we can wait until the child is old enough to tolerate local anesthesia surgery. The main advantage of surgery at this time is that the position of the eyelid can be adjusted during local anesthesia, which is highly controllable, and the function of the levator muscle may improve somewhat when the child is older, which can lead to satisfactory results. In cases where the upper lid obscures the pupil and affects vision, early surgery is needed to raise the eyelid and promote visual function.