We examined 18 cases of floppy eyelid syndrome, first reported in the Orient, in patients ranging in age from 11 to 55 years (mean 24 years); 16 were men and two were women. In contrast to previous reports in which almost all patients were obese men, only three of our patients were mildly obese. The most common abnormal corneal finding was punctate epithelial keratopathy (five patients-28%). Keratoconus was detectable in three patients (17%) overall; it was bilateral in one case and unilateral in two. Other miscellaneous corneal findings were corneal astigmatism and corneal opacity. In two cases, we found a familial tendency to skin hyperextensibility and joint hypermobility, and in one case, floppy eyelid syndrome developed after pars plana vitrectomy. The pathogenesis of the syndrome is still unknown, but our findings suggest that the more important pathogenetic risk factors are not obesity and sleeping pattern, but genetic collagen and/or elastin abnormality.