Fat soluble vitamin, found in liver, kidney, eggs and green vegetables. Role in corneal and conjunctival development 

Rare in the industrialised world but more common in developing countries 

Can occur in diseases causing malabsorption including chronic pancreatitis, coeliac disease, Crohn’s disease and cystic fibrosis due to fat malabsorption

Xerophthalmia (due to impaired lacrimal gland function and results in dry eyes, night blindness and can even result in total blindness)

Medical: Vitamin A supplements, pancreatic enzyme supplements if secondary to 

fat malabsorption due to pancreatic insufficiency 

Usually reversible, advanced xerophthalmia can be irreversible