Side effects? Some may experience irritation, or darkening of the upper eyelid skin along the lash line. In most cases, this darkening is reversible when stopped. There is a potential risk for periorbital fat loss, and intraocular pressure changes. There is a potential for increased brown iris pigmentation (brown darkening of the colored part of the eye), which is likely to be permanent. In the clinical trial, the incidence of all side effects, including brown hyperpigmentation of the iris was less than 4%. Do not apply directly into the eyes.