3. Melanin deficiency
Talking about health conditions that may cause blue eyes, the first medical explanation is regarding a lack of melanin pigment. This pigment is responsible for rendering eye color in individuals. A lack of this pigment results in blue or green eyes while sufficient amount of it renders the eye color brown.
4. Waardenburg syndrome
Besides pigmentation defect, another condition that may result in blue eyes is Waardenburg syndrome, which is a genetic optical condition. It may affect either of the eyes or both and may also impact hearing. It can also be a sign of ocular albinism, which causes severe ocular defects like involuntary eye movements and high sensitivity to light.