Aim. To study the effect of pH on the conjunctival cavity. Materials and methods. All patients underwent the following studies: Biomicroscopy of the conjunctival cavity, evaluation of the cosmetic effect of prosthetics, sensation and comfort, and bacterial culture of the discharge. The results of the study. As a result of the study, it was found that patients using ocular prostheses with concomitant diabetes mellitus have a pH shift in the conjunctival cavity to the alkaline side, which will lead to partial inflammatory reactions of the conjunctival cavity, resulting in a decrease in the desired cosmetic effect Conclusion. Diabetic patients require a lot of attention and a more thorough approach to meeting the conditions for normalizing the pH of the conjunctival cavity, and the terms of replacing the prosthesis, as a result, achieving a good cosmetic effect.