Damaging chemicals, wind, dust and the sun's ultraviolet rays can all cause clear bump, known as a pingueculum, to grow on the white of the eyeball, according to Summit Medical Group. The condition is more common in people who live in sunny climates or spend ample time outdoors.
As of 2015, the exact cause of pinguecula is unknown, although long-term exposure to sunlight and eye irritation are risk factors, according to MedlinePlus. The bump normally grows near the cornea, typically on the nasal side. It may have a yellowish appearance and can increase in size over time if not removed. If the bump occurs over the cornea, it is known as a pterygium. Although considered a separate condition, this type of bump occurs under similar circumstances. A standard eye exam is generally all that is necessary to make a diagnosis.
Although treatment is not necessary, patients may choose to have the bump removed for cosmetic reasons, and moisturizing eye drops may help prevent the area from swelling, as stated by MedlinePlus. Wearing high-quality sunglasses and avoiding irritating substances can help to prevent future pingueculum. Patients should call their doctor or optometrist if the bump changes in size, shape or color.