A naevus is typically a flat, benign, pigmented area that may appear inside the eye or on its surface. Naevae commonly appear on the choroid (the layer just behind the retina), the iris, and the conjunctiva. Naevae are similar to freckles, and don't typically change or grow.

Signs and Symptoms

• Brownish, freckle-like spot
• Usually flat

Detection and Diagnosis

Naevae of the conjunctiva or iris can be detected with a slit lamp microscope. If the naevus occurs within the eye, it is evaluated with an ophthalmoscope.

Treatment

Naevae are usually harmless, but it's always wise to monitor them for changes. This can be done with photos and sometimes ultrasound. The eye care practitioner will document the size, shape and whether the naevus is elevated. In rare cases, the naevus must be biopsied and examined for melanoma (cancer) cells.

Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.