What is Tonopen?
{{no sources|date=June 2023}} The Tono-Pen is a handheld device that's shaped like a large marker. A doctor can touch this device to your eye to measure the pressure. Pressure in the eyes greater than 22 [mm Hg] is considered higher than normal and can indicate ocular hypertension. While ocular hypertension is not an eye disease in itself, it is an indication that you could develop glaucoma. [[Category:Medical equipment]]