Cavaliers are also affected by ear problems, a common health problem among spaniels of various types, and they can have such other general conditions as hip dysplasia, which are common across many types of dog breeds. A disorder commonly found in Cavaliers is keratoconjunctivitis sicca, colloquially known as 'dry eye'. The usual cause of this condition is an autoimmune reaction against the dog's lacrimal gland (tear gland), reducing the production of tears. According to the Canine Inherited Disorders Database, the condition requires continual treatment and if untreated may result in partial or total blindness. This disorder can decrease or heal over time.A 1999 study of Cavaliers conducted by the Canine Eye Registration Foundation showed that an average of 30% of all Cavalier King Charles Spaniels evaluated had eye problems. They include hereditary cataracts, corneal dystrophy, distichiasis, entropion, microphthalmia, progressive retinal atrophy, and retinal dysplasia.