To characterize differences in upper and lower eyelid positions among different Korean age groups.

Digital photographs of 380 patients were retrospectively selected. Patients who had no known eyelid disorders or previous surgeries that could affect eyelid position were included. The marginal reflex distance 1 (MRD1) and marginal reflex distance 2 (MRD2) were measured from photographs using Image J software. Patients were divided into four groups for analysis: a child group, 0–20 years of age; a young adult group, 20–40 years of age; a middle age group, 40–60 years of age; and an elderly group, ≥60 years of age.

Total of 380 eyes from 380 patients were included. Mean age was 38.90 ± 22.79 years, and 200 (52.6%) were male. Mean MRD1s (mm) in each age group were: 0–20 years (n = 92), 2.94 ± 0.95; 20–40 years (n = 102), 3.23 ± 0.92; 40–60 years (n = 94), 3.33 ± 1.09; and ≥ 60 (n = 92), 2.42 ± 1.03. Mean MRD2s (mm) in each age group were: 0–20 years (n = 92), 5.37 ± 0.68; 20–40 years (n = 102), 5.66 ± 0.58; 40–60 years (n = 94), 5.29 ± 0.80; and ≥ 60 years (n = 92), 4.45 ± 0.86. The mean MRD1 was longest in the middle age group, and shortest in the elderly group. The mean MRD2 was longest in the young adult group, and shortest in the elderly group. The mean MRD1 (mm) was 2.90 ± 1.07 in males and 3.09 ± 1.03 in females. The mean MRD2 (mm) was 5.44 ± 0.68 in males and 4.95 ± 0.96 in females, and there was a statistically significant difference in the MRD2 between the two sexes ( p = 0.077, p =0.000, respectively).

Significant decreases were observed in the MRD1 and MRD2 with Koreans aged ≥ 60 years. Notably, the decrease in MRD2 in females was more significant than in males. This could be important reference values for successful eyelid surgery, especially in elderly patients. The amount of surgical correction during upper lid surgery should be determined according to the MRD1, in order to prevent overcorrection.