To compare distance visual acuity in Bulgarian patients over 18 years of age using two different methods - the Snellen method and the DIDIVAT digital online optotypes. For the purpose of this study, it is planned to examine native visual acuity (with and without prescribed optical correction), without additional mydriasis in both ways, of 150 Bulgarian patients (75 women and 75 men) over 18 years of age, hospitalized in a university eye clinic at St. George University Hospital and healthy volunteers willing to participate in the study. The statistical analysis that will be performed will aim to compare whether the two methods for determining distance visual acuity are identical in results, as well as to validate the application for the Bulgarian population.The study is expected to prove that the distance visual acuity of patients examined by both methods is identical.

Inclusion Criteria:

• Bulgarian speaking patients (75 women and 75 men) over 18 years of age, hospitalized in a university eye clinic at St. George University Hospital and healthy volunteers willing to participate in the study.

Exclusion Criteria:

• Patients of less than 18 years of age.

Bulgarian speaking patients (75 women and 75 men) over 18 years of age, hospitalized in a university eye clinic at St. George University Hospital and healthy volunteers willing to participate in the study.