Corneal dry spots are dry corneal spots that form due to the accumulation of corneal epithelium and are seen primarily in vitamin A deficiency diseases. This condition is an ocular manifestation of a systemic nutritional disorder, vitamin A deficiency. So why does vitamin A deficiency manifest? Vitamin A deficiency is mainly caused by insufficient intake: for example, vitamin A deficiency occurs after prolonged feeding of skimmed milk, soymilk and starchy foods without timely addition of hygienic A-rich liver, egg yolks, cod liver oil, and carotene-containing leafy green vegetables, carrots, tomatoes, and fruits. Breastfed children are less likely to develop vitamin A deficiency, but infants are at risk of early onset of vitamin A deficiency if their mothers have dietary and nutritional restrictions, if the mothers themselves are vitamin A deficient, and if their breast milk is low in retinol. The second factor causing vitamin A deficiency is the increased need for vitamin A in infants and young children: for example, premature babies have rapid growth and development, but their liver stores less vitamin A, so the demand for vitamin A is higher, and premature babies have poor digestion and absorption of fats, which makes them susceptible to vitamin A deficiency. Vitamin A deficiency is also easy to complicate when children have infections, especially serious infections such as measles, extended pneumonia, tuberculosis and high fever. Therefore, vitamin A deficiency is one of the causes of decreased resistance and recurrent infections, and infections in turn increase the demand for vitamin A, resulting in vitamin A deficiency, a reciprocal causal relationship. The third cause of vitamin A deficiency in babies is abnormal absorption and utilization of vitamin A storage. Since vitamin A is a fat-soluble vitamin, absorption of vitamin A in the small intestine requires the involvement of bile salts and fat. If the baby’s dietary fat content is too low, such as long-term skim milk, soy milk and starchy foods, it is easy to occur hygienic A deficiency; suffering from digestive diseases such as chronic diarrhea caused by gastrointestinal dysfunction can affect the digestion and absorption of vitamin A and carotene; liver disease, congenital biliary obstruction, severe malnutrition, other nutrient deficiencies (iron and zinc deficiencies) and so on will lead to the absorption and utilization of vitamin A storage abnormalities, resulting in vitamin A absorption and storage. Abnormalities in the utilization and storage of vitamin A can lead to vitamin A deficiency.