Brown spots in the eyes are common and often harmless. These spots represent accumulations of melanin, the natural pigment that gives color to our skin, hair, and eyes. Like freckles or moles on the skin, these pigmented areas can develop on various parts of the eye. While often benign, understanding their nature and when they might signal a need for professional evaluation is important for eye health.
Common Benign Brown Spots
One common type is iris freckles, small, dark brown spots on the surface of the iris, the colored part of the eye. These are typically flat and do not distort the iris tissue, resulting from melanin buildup, often due to sun exposure. Iris nevi are similar to iris freckles but are generally larger and extend deeper into the iris tissue, sometimes appearing as slightly elevated pigmented areas. While they can grow, iris nevi are usually benign and are monitored.
Another type is conjunctival nevi, pigmented spots appearing on the conjunctiva, the clear membrane covering the white part of the eye. These can range in color from yellow to dark brown and may contain small clear cysts. Often present at birth or developing early in life, they typically remain benign even if they change in color or size. Hormonal shifts, such as during puberty or pregnancy, and ultraviolet (UV) light exposure are factors that can influence their appearance.
Choroidal nevi are brown spots located in the choroid, a layer of tissue beneath the retina at the back of the eye. These internal spots are often detected during a comprehensive eye examination and appear as flat or minimally elevated, dark gray to brownish lesions. Composed of melanocytes, they are typically benign, though a small percentage carry a low risk of transforming into a more serious condition. Most choroidal nevi do not cause any symptoms and are discovered incidentally.
Signs That Warrant Medical Attention
Any noticeable change in an existing brown spot, such as an increase in size, alteration in shape, or a change in color, warrants immediate evaluation. A new brown spot appearing suddenly, especially if accompanied by other visual disturbances, also requires prompt medical attention.
Associated visual symptoms can indicate a more serious underlying issue. These include blurred vision, the sudden appearance or increase of floaters (small specks or cobwebs that drift across the field of vision), or flashes of light. Eye pain or discomfort, redness, or swelling of the eye in conjunction with a brown spot are also warning signs. In rare instances, a brown spot with these concerning changes or symptoms could signify ocular melanoma, a serious type of eye cancer.
Other signs include any change in the pupil’s appearance or size, or if the eyeball’s position seems to change. Professional assessment is important to differentiate between a harmless spot and one that may require intervention.
Evaluation and Monitoring by Eye Professionals
Eye care professionals employ various methods for evaluation and monitoring. A comprehensive eye examination is the primary step, often involving a slit-lamp exam to inspect the front structures of the eye, including the iris and conjunctiva. For spots at the back of the eye, such as choroidal nevi, an ophthalmoscopy allows the doctor to view the retina and choroid.
Advanced imaging techniques gain detailed insights into the spot’s characteristics and track changes. Optical Coherence Tomography (OCT) provides high-resolution cross-sectional images of eye tissues, useful for assessing the depth and structure of nevi. Ultrasound imaging measures the thickness and elevation of pigmented lesions, particularly in the choroid, helping differentiate benign spots from potentially malignant ones. Fundus photography captures detailed images of the back of the eye, creating a baseline for comparison during subsequent visits to monitor for growth or alterations.
Most benign brown spots do not require treatment, but regular monitoring is crucial to ensure stability. If a spot exhibits concerning features or changes, further diagnostic tests may be performed, and a specialist, such as an ocular oncologist, might be consulted. Early detection of any concerning changes improves outcomes for potentially serious conditions.