THE AIM of the study was to study the effect of wearing an eye prosthesis by patients with type 2 diabetes on the level of acid-base balance of the conjunctival cavity. MATERIALS AND METHODS. Biomicroscopy of the conjunctival cavity, the pH of the discharge from the conjunctival cavity and HbA1c in the blood were determined. CONCLUSIONS. The constant presence of an ocular prosthesis in the conjunctival cavity leads to a shift in the acid-base balance to the alkaline side, and the patient's history of diabetes also leads to the same result. The shift in the pH of the conjunctival cavity directly depends on the level of glycated hemoglobin, and the combination of these factors leads to a more aggressive shift of the pH to the alkaline side.