The liver is responsible for hundreds of functions, including filtering blood, synthesizing proteins, and metabolizing nutrients. When liver disease impairs these functions, systemic effects can manifest in seemingly unrelated parts of the body, including the eyes. Liver disease can cause blurry vision, and the mechanisms involve both neurological toxicity and nutritional deficits.
How Systemic Toxins Affect Vision
Advanced liver disease, such as cirrhosis, severely limits the liver’s ability to detoxify metabolic waste products. This failure allows neurotoxins, primarily ammonia, to bypass the compromised liver and travel to the brain. This buildup of ammonia is the central cause of a serious brain disorder called hepatic encephalopathy (HE).
The elevated ammonia levels cross the blood-brain barrier and interfere with neurotransmission and energy metabolism. While HE is most often associated with confusion and altered consciousness, the visual pathways and the occipital cortex—the brain’s visual processing center—can also be affected. This neurological interference directly impairs the brain’s ability to process visual information, leading to functional visual blurring.
In rare but severe cases, this neurotoxicity can manifest as transient cortical blindness, a temporary loss of vision despite the eyes being structurally healthy. Less severe but more common is a pervasive blurring or difficulty with visual coordination, which improves when ammonia levels are medically controlled. Bilirubin, a yellow pigment from the breakdown of red blood cells, also builds up in liver disease. While known for causing jaundice, its neurotoxic properties contribute to the impairment of neurological function, including visual clarity.
Nutritional Deficiencies and Eye Health
The liver plays a major role in the metabolism and storage of fat-soluble vitamins necessary for healthy vision. Impaired liver function, particularly chronic cholestasis or bile duct obstruction, reduces the secretion of bile salts needed for intestinal absorption. This malabsorption often leads to specific deficiencies that directly compromise ocular health and visual acuity.
Vitamin A (retinol) is the most frequently implicated nutrient, as the liver’s hepatic stellate cells store the body’s reserve. Liver scarring (fibrosis or cirrhosis) leads to the loss of these vitamin A-storing cells, further depleting the supply. A lack of this vitamin impairs the regeneration of rhodopsin, the light-sensitive pigment found in the rod photoreceptor cells of the retina.
The earliest and most common visual symptom of this deficiency is night blindness (nyctalopia), a form of blurring in low-light conditions. As the deficiency progresses, it can cause xerophthalmia, a severe dryness of the conjunctiva and cornea. This dryness leads to corneal damage, surface irregularities, and clouding, manifesting as persistent blurry vision. Reduced synthesis of Retinol Binding Protein 4 (RBP4), which transports Vitamin A to the eyes, further limits the nutrient’s availability.
Other Common Ocular Signs of Liver Disease
Beyond the direct causes of blurry vision, several other visible signs can indicate underlying liver dysfunction. The most recognized of these is scleral icterus, or jaundice, where the white part of the eye (sclera) turns yellow. This discoloration is caused by the systemic buildup of bilirubin, which deposits in the elastic tissue of the sclera.
Certain specific liver conditions produce unique ocular findings. Wilson’s disease, an inherited disorder preventing the body from properly eliminating copper, causes copper to accumulate in various organs, including the cornea. This buildup creates distinctive brownish-green or golden rings around the edge of the iris, known as Kayser-Fleischer rings. These rings do not affect vision but are a diagnostic sign.
Systemic inflammation and clotting issues associated with advanced liver disease can also affect the eyes. Impaired synthesis of clotting factors can lead to subconjunctival hemorrhages, appearing as red patches on the white of the eye due to ruptured blood vessels. Autoimmune liver conditions, such as Primary Biliary Cholangitis, may co-exist with disorders like Sjögren’s syndrome, leading to chronic dry eyes that cause irritation and intermittent visual blurring.