The whites of the eyes, known medically as the sclera, can sometimes take on a greyish color as people age. This discoloration is usually harmless, but in some cases it can signal an underlying health condition. There are a few potential causes for grey sclera, which this article will explore in depth.
Anatomy of the Eye
To understand why the sclera may turn grey, it helps to first review the anatomy of the eye. The sclera is the opaque, fibrous, protective outer layer of the eyeball. It helps maintain the structure and shape of the eye. Under the sclera is the choroid, a thin, vascular layer containing blood vessels that supply oxygen and nutrients to the eye. The conjunctiva is a clear membrane covering the sclera and inside of the eyelids.
The iris and pupil sit behind the cornea, the clear front portion of the eye. The iris is the colored part of the eye, while the pupil is the dark opening in the center that allows light to enter. Behind the iris is the lens, which focuses light onto the retina at the back of the eye. The retina contains photoreceptor cells that convert light into electrical signals transmitted to the brain via the optic nerve.
Normal Age-Related Changes
As people get older, the sclera can gradually lose some of its white color and take on a slightly grey, yellowish, or blueish hue. By age 80, approximately half of adults will have some greyish discoloration of their scleras.
Causes
Age-related changes to the collagen and elastin fibers in the sclera lead to a thinning of this tissue. With less opacity, the underlying choroidal blood vessels show through more, causing a greyish coloring. The pigment cells in the sclera known as melanocytes also tend to increase with age, resulting in darker patches.
Prevalence
A study published in Ophthalmology in 2003 found the prevalence of scleral discoloration increases with age:
| Age Group | Prevalence |
| 50-59 years | 10% |
| 60-69 years | 18% |
| 70-79 years | 44% |
| Over 80 years | 51% |
The discoloration occurred more often in the nasal and temporal areas of the sclera near the corners of the eyes.
Significance
For most healthy adults, age-related greyish discoloration of the sclera is harmless and does not affect vision. However, a study in the British Journal of Ophthalmology did find an association between scleral thinning and the severity of age-related macular degeneration (AMD), the leading cause of vision loss in older adults. The greyish sclera may be a useful clinical marker for identifying patients at higher risk for advanced AMD.
Other Causes of Grey Sclera
While age-related changes are the most common cause of grey sclera, several other conditions can also contribute to this discoloration:
High Myopia
People with severe nearsightedness, or myopia, are more likely to develop a bluish-grey discoloration of the sclera usually first appearing around age 40. The thinning of the sclera associated with high myopia allows the underlying uveal tissue to show through. This bluish discoloration is benign and requires no treatment. Glasses, contact lenses or refractive surgery can correct the vision problems caused by myopia but do not reverse scleral discoloration.
Pinguecula
Pingueculae are small, yellowish deposits of protein and fat that build up on the conjunctiva, most often near the nose. As these deposits increase with age, they can create patches of greyish discoloration on the sclera. Pingueculae also may be related to sun exposure. They do not impair vision unless they enlarge significantly and cause astigmatism by pushing on the cornea. Lubricating eye drops can help manage irritation from pingueculae. Larger ones can be surgically removed if necessary.
Scleritis
Scleritis is inflammation of the sclera that can cause significant redness, tearing, light sensitivity and eye pain. It may occur as a complication of autoimmune disorders like rheumatoid arthritis. The inflamed sclera often takes on a bluish hue. Scleritis requires urgent medical treatment with oral NSAIDs, corticosteroids or other immunosuppressants to relieve swelling and prevent blindness from scleral thinning or perforation. Treating the underlying autoimmune condition can also help.
Jaundice
Jaundice is a yellowish discoloration of the skin and eyes that occurs when excess bilirubin builds up in the blood. Bilirubin is a pigment produced from the breakdown of red blood cells in the liver. The whites of the eyes take on a greyish, pale yellow hue with jaundice. Common causes include liver diseases like hepatitis and cirrhosis, gallstones, infections, certain medications or hereditary blood disorders. Jaundice often resolves by treating the underlying condition. But high bilirubin levels can be dangerous and sometimes require interventions like phototherapy or blood filtering.
When to See an Eye Doctor
For adults over 50 noticing new greyish discoloration of the sclera, it usually requires no medical treatment. However, schedule an exam if it is accompanied by:
– Pain or redness in the eye
– Light sensitivity
– Vision changes
– Headache
– Excessive tearing or discharge
See an ophthalmologist promptly if you have jaundice to determine the cause and treat any serious liver disease. Also consult an eye doctor about grey sclera if you have other autoimmune symptoms or a family history of eye inflammation. Eyecare professionals can evaluate for concerning conditions like scleritis and recommend proper management.
Prevention
While some scleral discoloration is an inevitable part of aging, practicing healthy habits may help minimize changes:
– Wear UV-blocking sunglasses outside
– Don’t smoke
– Eat an antioxidant-rich diet with fruits, vegetables and omega-3s
– Control other autoimmune conditions through medication
– Have regular eye exams to detect any problems early
Cosmetic Options
For those concerned about the cosmetic appearance of grey sclera, several options exist to restore a whiter appearance:
Scleral Contact Lenses
Gas permeable scleral lenses fit over the entire eye, masking any discoloration. They do not improve vision but provide a cosmetic effect. Lenses must be properly fitted by an optometrist and require maintenance like daily cleaning.
Scleral Tattooing
Ink can be injected into the sclera to create a white backdrop that hides underlying bluish hues. A tattooing tool allows application of white pigment just under the conjunctiva. It takes about 15-30 minutes and can last several years before requiring touch up. Risks include infection and vision changes if too much ink is used.
Laser Treatment
A YAG laser can remove melanin pigment deposits in the sclera that cause greyish spots. Performed under topical anesthesia, the technique takes 15-20 minutes. Several sessions may be necessary to achieve desired results. Potential side effects include swelling, bleeding, infection and increased eye pressure.
Allograft Transplant
Scleral grafting surgically replaces a discolored portion of sclera with donated tissue. It permanently restores a white appearance but requires general anesthesia and a lengthy recovery. Risks include rejection, infection and vision loss. Due to complications, grafting is reserved for cases of severe scleral thinning that threaten eye rupture.
Conclusion
The development of greyish discolored sclera is usually a harmless part of the aging process. But changes in eye appearance should always be discussed with an ophthalmologist, especially when accompanied by pain or vision problems, to rule out rare inflammatory conditions. While no treatment is required in most cases, several cosmetic options like scleral lenses can improve the look of the whites of the eyes. With a healthy lifestyle and proper eye protection, individuals can age gracefully while maintaining the health and function of their eyes.
