Why Are the Whites of My Eyes Yellow? Gilbert's Syndrome and the Other Causes

Short answer: the most common harmless reason for a yellow tinge in the whites of the eyes is Gilbert's syndrome — a common, inherited difference in how the liver processes bilirubin. It does not damage vision and needs no treatment. But yellow eyes have several other causes, and some of them are not harmless, so the yellowing itself is always worth having looked at.

The most common harmless cause: Gilbert's syndrome

Gilbert's syndrome is an inherited variation in the UGT1A1 gene, which codes for the liver enzyme that processes bilirubin — the yellow pigment left over when red blood cells are broken down. People with the syndrome run that enzyme at roughly 30–50% of normal capacity, so unconjugated bilirubin sits a little higher in the blood than usual, generally under 4 mg/dL (about 68 µmol/L).

It is not rare. Reported prevalence runs from about 2% to 20% depending on ancestry, which makes it one of the more common inherited conditions an optometrist sees across a career without anyone in the room realising it is there. The liver is otherwise normal, the prognosis is excellent, and no treatment is required.

Why does it show in the eyes first?

Because bilirubin binds readily to elastin, and the tissue at the front of the eye is rich in it.

Jaundice usually becomes visible once serum bilirubin reaches roughly 2–2.5 mg/dL (34–43 µmol/L), and the front of the eye is where a clinician looks first — mild jaundice is best seen by examining the eyes in natural daylight. Skin yellowing typically needs a higher level again, so a person can look entirely normal everywhere except the eyes.

One correction worth making, since most textbooks still get it wrong: the pigment is not in the sclera. Bilirubin collects in the conjunctiva and the superficial episclera, which are full of elastin; the sclera proper is not. Conjunctival icterus is the accurate term, and it has been argued for in the literature since Kuiper's 2001 paper in Annals of Internal Medicine and the 2005 correspondence in American Family Physician that followed it.

Why does the yellow come and go?

Bilirubin in Gilbert's syndrome is not a fixed number — it moves with the load on the body. Recognised triggers include fasting or skipping meals, febrile illness, dehydration, physical exertion, sleep deprivation, menstruation and stress. Reducing daily intake to around 400 kcal can raise bilirubin two- to threefold within 48 hours.

This is why people with Gilbert's syndrome so often report that their eyes “go yellow when I'm run down”. They are reading a real signal.

Does Gilbert's syndrome damage eyesight?

No. There is no retinal, optic nerve or corneal disease attributable to Gilbert's syndrome, and no eye treatment is indicated for it.

The more interesting question is the opposite one. Bilirubin is a potent natural antioxidant, and mildly raised levels have been linked in observational research to lower rates of small-vessel complications. A 2021 case-control study in Metabolism Open comparing 50 people who had both Gilbert's syndrome and type 2 diabetes against 50 matched controls found retinopathy in 18% versus 40% (odds ratio 0.24). A 2026 analysis of 8,274 people with diabetes in the NHANES dataset found higher total bilirubin associated with lower odds of diabetic retinopathy (adjusted odds ratio 0.77), with a genetic arm suggesting a causal effect for proliferative disease specifically (odds ratio 0.91, p = 0.044).

That evidence is worth reading carefully rather than enthusiastically. The case-control study is small, the genetic signal is borderline and limited to advanced disease, and none of it is a reason for anyone with diabetes to ease off retinal screening. It is a plausible protective association, not a shield.

Yellow eyes that are not Gilbert's syndrome

This is the part that matters clinically. The risk is not the condition — it is diagnosing yourself with it in the bathroom mirror. Yellowing at the front of the eye can also reflect:

• A pinguecula — a raised yellowish patch of degenerated conjunctival tissue, usually on the nose side of the eye, caused by UV and wind exposure. It is localised, not a diffuse wash of colour.
• Age-related lipid change in the conjunctiva, which can give the whites a generally creamier tone.
• Carotenoderma from a high intake of carrots, kumara or pumpkin, which yellows the skin but spares the eyes — a useful distinguishing sign.
• Genuine liver or bile-duct disease — hepatitis, gallstones, alcohol-related liver disease, haemolysis, or a drug effect. These are the ones that must not be brushed off.

The distinction is not made by looking in a mirror. It is made by examining the eye and, where the picture is icteric, by a blood test.

What to do if the whites of your eyes look yellow

Have it looked at. An eye examination can tell the difference between a pinguecula, an age-related conjunctival change and true conjunctival icterus, and can document the appearance for comparison later. If the picture is icteric, the next step is a blood test through your GP — an isolated raised unconjugated bilirubin with otherwise normal liver enzymes is the signature of Gilbert's syndrome.

If that is what it turns out to be, the answer is reassuring: nothing to treat, nothing to restrict, and no threat to your sight. It is still worth knowing. It explains why your eyes change after a skipped lunch or a rough week, and it is relevant when certain medicines are prescribed, because the same liver enzyme handles some of them.

Common questions

Can an optometrist tell if I have Gilbert's syndrome?
An optometrist can establish whether the yellowing sits in the conjunctiva and is consistent with icterus, and can rule out the ocular surface causes that mimic it. Confirming Gilbert's syndrome itself requires a blood test.

Does Gilbert's syndrome cause dry eye or blurred vision?
There is no established link between Gilbert's syndrome and dry eye, blurred vision or any other eye condition. Symptoms alongside yellow eyes should be assessed on their own merits.

Will the yellow ever go away?
It fluctuates. Levels typically fall with regular meals, adequate hydration, sleep and recovery from illness, and the eyes look clearer as they do.

If only one eye looks yellow, is that Gilbert's syndrome?
No. Icterus affects both eyes. Yellowing confined to one eye, or to one patch, points to a local cause at the eye surface and should be examined.

Our optometrists

Assessment of the ocular surface and anterior eye — including working out what a yellow eye actually is — is part of the clinical practice of all of our therapeutically qualified optometrists: partners Jagrut Lallu and Jacqueline Rowe, and optometrists Emilie Lawson, Jason Shen, Anjali Hira, Stella Wong and Jessica Wood.

Book a comprehensive eye examination with our team: new patients book here or existing patients book here. If the yellowing is new, marked, or comes with pain, dark urine, pale stools or feeling unwell, contact your GP the same day rather than waiting for a routine appointment.

This article is general information, not a diagnosis. Sources: Gilbert Syndrome, StatPearls (NCBI Bookshelf); Jaundice, Merck Manual Professional Edition; “Use of the Term Conjunctival Icterus Instead of Scleral Icterus”, American Family Physician 2005;71(1):49; Patients with Gilbert syndrome and type 2 diabetes have lower prevalence of microvascular complications, Metabolism Open 2021; Association between serum bilirubin and diabetic retinopathy: NHANES 1999–2018 and Mendelian randomization study, Diabetology & Metabolic Syndrome 2026.