A choroidal nevus is a benign, pigmented lesion found in the choroid layer of the eye, which is located between the retina and the sclera. It is often referred to as a "freckle" or "mole" in the eye and is usually asymptomatic. Choroidal nevi are typically discovered during routine eye examinations and are monitored for any changes in size or appearance that may indicate a potential transformation into a malignant melanoma.