A white dot in the eye can be concerning, with causes ranging from harmless surface growths to more significant internal changes. Understanding these possibilities helps determine when professional evaluation is necessary for diagnosis and care.
Common Causes on the Eye’s Surface
White dots on the eye’s outer layers, like the conjunctiva, often result from common, benign conditions. A pinguecula is a yellowish-white bump on the conjunctiva, the clear membrane covering the white part of the eye. These growths typically appear near the nose but can also form elsewhere. Pingueculae are often caused by prolonged exposure to sunlight, wind, or dust. While generally harmless, they can sometimes cause irritation or a foreign body sensation.
A pterygium, sometimes called “surfer’s eye,” is another surface growth. This fleshy, triangular growth begins on the conjunctiva, usually near the nose, and can extend onto the cornea. Like pingueculae, pterygia are linked to chronic exposure to UV light, wind, and dust. Though often asymptomatic at first, they can cause redness, irritation, or a foreign body sensation. Foreign bodies, such as dust or debris, can also temporarily appear as a white dot, causing irritation until removed.
Corneal Conditions
White dots on the cornea, the clear front surface of the eye, often signal a more serious issue needing prompt attention. A corneal ulcer is an open sore on the cornea that typically appears as a white or gray spot. These ulcers frequently result from infections, including bacterial, viral, or fungal keratitis, or can be caused by severe dry eye or eye injuries. Bacterial keratitis is often associated with improper contact lens hygiene, while viral keratitis (e.g., herpes simplex) can also cause ulcers.
Corneal ulcers can cause pain, redness, light sensitivity, and blurred vision. Untreated, they may lead to permanent vision loss due to scarring. Corneal scars, resulting from previous infections, injuries, or certain dystrophies, appear as opaque white spots. These scars can obstruct light entry, leading to hazy or blurry vision, with the impact depending on their size and location.
Changes Within the Eye
A white dot within the eye can indicate changes in internal structures, particularly the lens. Cataracts, a common age-related condition, involve the clouding of the eye’s natural lens, located behind the iris. While early cataracts may not be outwardly visible, as they progress, the lens can develop cloudy patches appearing whitish or yellowish. This clouding occurs when proteins within the lens break down, scattering light and preventing clear images from reaching the retina.
Different types of cataracts can present with varying appearances. For instance, cortical cataracts begin as white, wedge-shaped spots on the outer edge of the lens. In more advanced stages, the entire lens can become milky white or amber, significantly affecting vision. Though cataracts typically develop slowly, they can cause symptoms such as blurred vision, faded colors, difficulty with night vision, and glare around lights. A white dot usually indicates a localized area of opacification within the lens.
When to Seek Professional Evaluation
Any new or changing white dot in the eye warrants professional evaluation by an eye care specialist. Prompt medical attention is important if the white spot is accompanied by symptoms such as eye pain, redness, or a foreign body sensation. Additionally, any sudden changes in vision, including blurriness, light sensitivity, or halos around lights, should prompt an immediate visit.
These symptoms can indicate underlying conditions that could lead to lasting vision problems if not addressed quickly. An eye care professional can accurately diagnose the cause of the white dot through a comprehensive eye examination. Early diagnosis allows for appropriate management, which can help preserve vision and prevent complications.