Eye pressure, also known as intraocular pressure (IOP), refers to the fluid pressure inside the eye. This pressure is essential for maintaining the eye's shape and ensuring proper function. It is measured in millimeters of mercury (mmHg) and can vary throughout the day. Normal eye pressure typically ranges from 10 to 21 mmHg. High eye pressure can be a risk factor for glaucoma, a condition that can lead to vision loss if not treated. Regular eye exams are important for monitoring IOP, as elevated levels may not show symptoms until significant damage has occurred.