A bili light is a phototherapy tool to treat newborn jaundice

Jaundice

Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...

 (hyperbilirubinemia) which in higher levels causes brain damage (kernicterus

Kernicterus

Kernicterus is damage to the brain centers of infants caused by increased levels of unconjugated bilirubin. This may be due to several underlying pathologic processes. Newborn babies are often polycythemic. When they break down the erythrocytes, one of the byproducts is bilirubin, which circulates...

), leading to cerebral palsy

Cerebral palsy

Cerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....

, auditory neuropathy, gaze abnormalities and dental enamel hypoplasia. The therapy uses a blue light (420-470 nm) that converts bilirubin

Bilirubin

Bilirubin is the yellow breakdown product of normal heme catabolism. Heme is found in hemoglobin, a principal component of red blood cells. Bilirubin is excreted in bile and urine, and elevated levels may indicate certain diseases...

 so that it can be excreted in the urine and feces. Soft eye shields are placed on the baby to protect their eyes from damage that may lead to retinopathy

Retinopathy

Retinopathy is a general term that refers to some form of non-inflammatory damage to the retina of the eye. Frequently, retinopathy is an ocular manifestation of systemic disease.-Pathophysiology:Causes of retinopathy are varied:...

due to the bili lights.