Lash ptosis (LP) is one of the important factors to be considered in blepharoplasty or correction of ptosis, but LP is an often overlooked symptom. We evaluate normal variations in the degree of LP to analyze the relationship between LP and its associated factors in Asians. One-hundred and sixty patients without ptosis and 16 patients with acquired ptosis were included in this study. We measured the degree of LP, marginal reflex distance 1, levator function, and presence or absence of a double fold. A significant difference was observed in LP rating between the nonptosis and acquired ptosis groups (P = 0.00), along with a significant correlation between LP rating and marginal reflex distance 1 (r = -0.272, P < 0.01), levator function (r = -0.170, P < 0.01), and absence or presence of double fold (r = -0.233, P < 0.01). Our results may be beneficial in the design of a basic plan for Asian patients with LP at the time of upper eyelid surgery, such as blepharoplasty or correction of ptosis.