The choroid is a thin, variably pigmented, vascular tissue forming the posterior uvea. It joins the ciliary body anteriorly and lies between the retina and sclera posteriorly.

Why choroid is pigmented?

The dark-colored melanin pigment in the choroid absorbs light and limits reflections within the eye that could degrade vision. 1 The melanin is also thought to protect the choroidal blood vessels against light toxicity. The choroidal pigment is what causes “red eyes” when flash photographs are taken.

Is choroid black in colour?

Choroid is bluish black in colour due to presence of melanin pigment in excess. The dark colour also reduces internal reflection in the eye ensuring that the image produced is not blurred.