Whether chronic dry eyes can lead to yellowing of the whites of the eyes addresses two distinct processes: a localized ocular surface condition and a systemic health indicator. Chronic dry eye (keratoconjunctivitis sicca) involves a deficiency or instability in the tear film protecting the eye’s front surface. The yellow discoloration of the eye, referred to as scleral icterus, is a physical sign of an underlying issue affecting the entire body. Understanding the biological mechanisms of each condition separately is necessary to determine if one can cause the other.
Understanding Dry Eye Syndrome
Dry eye syndrome is a disorder of the tear film and the ocular surface, characterized by a loss of tear film stability. The tear film is a complex, three-layered structure that must remain balanced to lubricate the eye, deliver oxygen, and protect against infection. Disruption in the watery or oily components leads to rapid tear evaporation or insufficient tear production.
This instability triggers inflammation on the surface of the eye, involving the conjunctiva and the cornea. When the tear film breaks down, it causes hyperosmolarity, meaning the tear fluid becomes excessively salty and damages surface cells. This activates immune cells, perpetuating a chronic inflammatory state that causes common symptoms of grittiness, burning, redness, and blurred vision.
The condition is localized to the eye’s front surface. While chronic inflammation can cause the blood vessels on the conjunctiva to become noticeably red, the biological processes are confined to the surface of the eye. Dry eye syndrome does not involve the systemic organs or circulating pigments that change the color of the sclera itself.
Systemic Causes of Eye Yellowing
The yellowing of the eye, or scleral icterus, is a direct result of an excessive buildup of the yellow pigment bilirubin in the bloodstream (hyperbilirubinemia). Bilirubin is a byproduct created when the body recycles old or damaged red blood cells. The resulting bilirubin must be processed by the liver.
A healthy liver filters this pigment from the blood and modifies it, making it water-soluble so it can be excreted. This processed bilirubin is then released into the bile, which moves through the bile ducts for elimination. Scleral icterus occurs when this systemic process is disrupted, causing bilirubin levels to rise significantly.
This elevation is a sign of a systemic problem, which can include liver diseases like hepatitis or cirrhosis, or issues that obstruct the flow of bile, such as gallstones. Because the sclera has a high elastin content, it is often one of the first places where the systemic accumulation of bilirubin becomes visible.
Is There a Direct Connection?
Dry eyes do not directly cause the yellowing of the eyes because the two conditions originate from completely separate biological mechanisms. Dry eye is an ocular surface disease, while scleral icterus indicates systemic dysfunction related to processing and excreting bilirubin.
A common point of confusion arises because chronic irritation from dry eyes can sometimes lead to the growth of a benign, slightly yellow bump called a pinguecula. This is a localized deposit of protein and fat, not a systemic pigment change, and it is easily mistaken for icterus. The pinguecula is typically raised and located close to the edge of the cornea, whereas true icterus is a uniform yellowing of the entire sclera.
It is possible for a person to experience both dry eyes and eye yellowing simultaneously, but this is due to a shared underlying systemic cause. Certain autoimmune diseases, such as Sjögren’s syndrome, can trigger chronic inflammation that attacks both moisture-producing glands and the liver. Some medications or chronic liver conditions can also directly affect both tear production and liver function.
If the whites of the eyes develop a yellow tint, it is a significant medical sign that requires immediate evaluation by a healthcare professional. While dry eyes are a localized discomfort, persistent yellowing indicates a need to diagnose the underlying systemic issue affecting red blood cell breakdown, the liver, or the bile ducts.