Mucinlike glycoprotein from tears and conjunctival goblet cell densities were determined in normal subjects and in patients. The results indicated that although there was a statistically significant decrease, a substantial amount of mucinlike glycoprotein was present in tears from patients with ocular cicatricial pemphigoid (OCP), radiation keratitis, and corneal anesthesia. In the same patients, the goblet cell count was profoundly decreased in OCP and radiation keratitis, well out of proportion to the modest fall in mucinlike glycoprotein. This indicated that the tear mucin content shows minimal variation over a great variation in goblet cell density, suggesting that while moderate mucin deficiency may be associated with surface abnormalities, such mucin deficiency may not be the only cause of the ocular surface epithelial problems characteristic of these diseases. In addition, it is proposed that the goblet cell content of the conjunctiva is a sensitive indicator of primary ocular surface disease.