a condition due to a deficiency of vitamin a where the conjunctiva and cornea become dry. the condition starts with conjunctival xerosis and night blindness and progresses to corneal xerosis and, later, a severe condition called keratomalacia.
xerophthalmia: dry eyes. xerophthalmia can be associated with systemic diseases, such as sjogren's syndrome, systemic lupus erythematosus, and rheumatoid arthritis; deficiency of vitamin a; and use of some medications. it results from inadequate function of the lacrimal glands, which produce tears. when xerophthalmia is due to vitamin a deficiency, the condition begins with night blindness and conjunctival xerosis (dryness of the eye membranes), progresses to corneal xerosis (dryness of the cornea), and in its late stages develops into keratomalacia (softening of the cornea). treatment depends on the severity of the condition and ranges from artificial tears and ointments to plugging of the tear ducts. also known as conjunctivitis arida. medicinenet.com
an early symptom of vitamin a deficiency is night blindness, which is caused by a disorder of the retina. soon thereafter, the whites (conjunctiva) and corneas of the eyes may become dry and thick—a condition called xerophthalmia. xerophthalmia is particularly common among children who have a severe deficiency of calories and protein, which includes inadequate intake of vitamin a. foamy deposits (bitot spots) may appear in the whites of the eyes. the dry cornea may soften and deteriorate, and blindness may result. vitamin a deficiency is a common cause of blindness in developing countries. merckmanuals.com