To report three cases of heterochromia iridis, asymmetry of iris pigmentation, which are categorized in three main groups: idiopathic, congenital and acquired.

Case 1: A 25-year-old female, referred to our clinic in June 2019 complaining of different colors of her both eyes since childhood, seeking for treatment. There was no remarkable point in her past ocular and systemic history. On examination, right eye was green and the sound eye was brown. Other ophthalmic examinations were normal. She had idiopathic type of heterochromia.

Case 2: A 20-year-old medical student was seen because of her right upper lid droop and lighter color since birth. Examination revealed complete visual acuity of 20/20 in both eyes. There was a slight ptosis on the right eye, but levator function was good on both sides. The iris color on the right side was lighter than the other one. The right pupil was miotic. By performing phenylephrine test, congenital Horner’s syndrome was confirmed. Case 3: A 36-year-old male came to our clinic complaining of decreased visual acuity and color change of his left eye gradually since 27 years ago, with occasionally redness of his left eye. No systemic disease was noted. His right eye was green and the fellow eye was blue. Examinations of her left eye revealed stellate keratic precipitates over corneal endothelium, 1+ cell presence in anterior chamber, 2+ vitritis and significant posterior subcapsular cataract. Confocal scanning confirmed the diagnosis of Fuchs' Heterochromic Iridocyclitis. His vision improved to 10/10 after cataract surgery.

Comprehensive ocular and systemic evaluations are vital to differentiate the various types of heterochromia and facilitate the treatment of hypo or hyper-chromic eye.