While some natural eye colors can appear golden, a distinct yellowing of the whites of the eyes (sclera) typically signals an underlying medical concern. These natural variations result from unique pigment combinations within the iris, differing significantly from medical yellowing.
Natural Eye Colors That Appear Yellow
Natural eye colors can present with a distinct yellow or golden appearance due to pigment distribution in the iris. Amber and some hazel shades are healthy and differ from medically induced yellowing. These hues stem from the interplay of melanin and lipochrome, two key pigments.
Amber eyes are characterized by a solid golden, yellowish, or coppery tint, often described as resembling the gemstone. This striking color is largely attributed to a higher concentration of a yellow pigment called lipochrome, also known as pheomelanin, combined with low levels of melanin. Unlike other eye colors, amber typically displays a uniform shade across the iris, making it distinct from the multi-tonal appearance of hazel eyes. This eye color is considered rare, present in about 5% of the global population.
Hazel eyes, on the other hand, are a complex blend of brown, green, and gold. They often appear to shift in color depending on lighting conditions. The yellow or golden specks and overall hue in hazel eyes result from a moderate amount of melanin in the iris’s anterior border layer, combined with light scattering, and also involve the presence of lipochrome. While hazel eyes can contain golden tones, their varied composition of colors distinguishes them from the solid golden appearance of amber eyes. The human eye does not contain actual yellow pigments; these colors are optical effects created by the amount and distribution of melanin and lipochrome, along with how light scatters within the iris.
Medical Causes of Eye Yellowing
Yellowing of the whites of the eyes, medically termed scleral icterus, most commonly indicates jaundice. Jaundice occurs when excess bilirubin accumulates in the bloodstream, depositing in body tissues, including the sclera. Bilirubin is a yellowish pigment formed when old red blood cells break down. Normally, the liver processes this bilirubin, making it part of bile for excretion.
Problems at various stages of bilirubin processing can lead to its buildup. Liver diseases are a primary cause, as a damaged or inflamed liver struggles to filter bilirubin effectively. Conditions such as hepatitis, cirrhosis, and non-alcoholic fatty liver disease impair the liver’s function. When the liver cannot properly process bilirubin, it leaks into the blood, leading to yellowing of the eyes and skin.
Issues with the gallbladder and bile ducts can also cause jaundice. The gallbladder stores bile, and the bile ducts transport it from the liver to the small intestine. Obstructions, such as gallstones or tumors in the bile ducts, prevent bilirubin-containing bile from flowing out of the liver. This blockage causes bilirubin to back up into the bloodstream, resulting in yellow eyes.
Pancreatic disorders can similarly lead to jaundice because the pancreas is closely located to the bile duct. Inflammation of the pancreas, known as pancreatitis, or pancreatic cancer can press on and block the bile duct. When the bile duct is obstructed, bile and its bilirubin content cannot reach the intestines for excretion, causing a systemic buildup. This type of obstruction-induced jaundice often presents with additional symptoms like abdominal pain.
Certain blood disorders can also contribute to yellow eyes. Hemolytic anemia, for instance, involves the rapid breakdown of red blood cells. This accelerated destruction releases an excessive amount of bilirubin into the blood, more than the liver can efficiently process. Other less common genetic conditions, such as Gilbert’s syndrome, involve a reduced ability of the liver to process bilirubin, leading to intermittent yellowing, though it is usually considered harmless.
Excessive intake of carotene-rich foods, a condition called carotenemia, can cause skin to appear yellowish. However, this condition typically affects the skin more prominently than the eyes, and the sclera usually remains white. Therefore, yellowing of the sclera is a more specific indicator of bilirubin-related issues.
When Yellow Eyes Are a Concern
Any yellowing of the whites of the eyes (scleral icterus) warrants prompt medical evaluation. This discoloration indicates an underlying health issue, particularly related to bilirubin processing. Seeking medical attention becomes even more urgent if yellow eyes are accompanied by other symptoms.
These can include unexplained fatigue or weakness, persistent nausea, or vomiting. Changes in bodily excretions, such as dark-colored urine or pale, clay-colored stools, are also important signs to note, as they further suggest issues with bilirubin excretion.
Additional symptoms that should prompt immediate medical consultation include abdominal pain, particularly in the upper right quadrant, which might radiate to the back. Itching of the skin without a visible rash, unexplained weight loss, or a loss of appetite are also concerning. The presence of fever, chills, or new-onset confusion indicates a serious condition.
Ignoring yellow eyes or delaying medical attention can have serious health consequences, as underlying conditions require timely diagnosis and treatment. Early detection allows healthcare professionals to identify the cause and initiate treatment, preventing complications and improving outcomes. Always consult a healthcare provider for an accurate diagnosis.