Glaucoma is an eye disease that damages the optic nerve, it cause blindness if not diagnosed and treated properly. The major risk factor for the development and progression of glaucoma is increased intraocular pressure. Colonoscopy is one of the most preformed world wide screening exam. It is used to detect colon cancer at its early stages. As part of this examination, the examiner inflates the inspected colon with air in order to increase the colon lumen for better visualization of the colon. As a consequence of the insufflation the intrabdominal pressure increases as well. the increase in intrabdominal pressure could increase intraocular pressure. The aim of this study is to evaluate the intraocular pressure increase while preforming colonoscopy.

Inclusion Criteria:

• Age >18.
• Patients referred by a gastroenterologist for a colonoscopy examination.
• Patients the are interested in participating in this study and who are able to sign an informed consent.

Exclusion Criteria:

• Family history of Glaucoma - first degree relatives.
• Patients with known ocular disease, excluding refraction.
• Patients receiving eye pharmacologic treatment.
• Patients with known allergies to Oxybuprocaine Hydrochloride drops.

The study population are healthy examinees, undergoing routine colonsocopy examination. All have no ocular disese and family history of glucoma.