Ptosis is one of the most frequently asked questions from patients, especially regarding the timing of surgery, so we are here to talk about it in detail in the hope that it will be helpful to patients and parents of children with ptosis. Without going into the causes, clinical manifestations and diagnosis of ptosis, we will focus on the classification and timing of surgery for various types of ptosis. Congenital ptosis includes simple ptosis and ptosis with other abnormalities: ptosis with extraocular muscle paralysis; lid slit syndrome; and mandibular-transient syndrome. Acquired ptosis includes: traumatic ptosis; myogenic ptosis; tenogenic ptosis; neurogenic ptosis; mechanical ptosis The timing of surgery for congenital ptosis is determined on a case-by-case basis: If the ptosis does not completely obscure the pupil, does not affect the patient’s visual development, and the child does not have strabismus, compensatory head position, etc., he or she may choose to undergo surgery at age 3 to 5 years or even later. Surgery. For severe ptosis, which will definitely affect visual development, surgery can be performed earlier, around 2 years of age, to prevent amblyopia. In cases with extraocular muscle paralysis, surgery is performed on the eye muscles before correcting ptosis. In microphthalmia syndrome, considering the surgical results, the surgery is usually performed in stages, with the inner and outer canthus first and the upper lid ptosis corrected after six months. Mandibular-transient syndrome generally improves with growth and development, so it is usually observed first, and surgery can be considered after the pubertal period when symptoms are still present. Acquired ptosis is usually treated for the primary condition first, and surgery can be considered after the condition has stabilized for about six months with no improvement in symptoms. Finally, I would also like to say that any surgery has risks, and there is an oxymoron between surgical results (large lid fissure) and eye protection (small lid fissure), so it is important to weigh all aspects and not sacrifice the eye for the pursuit of aesthetics. The surgical approach also depends on each patient’s individual circumstances.