Final answer:
The eye's shape is maintained by a liquid called intraocular pressure. Impaired circulation can lead to glaucoma, a damaging eye condition. Regular testing is recommended, especially for those over 40.
Step-by-step explanation:
The kind of liquid that keeps the eyes at a certain pressure is governed by intraocular pressure. It is crucial for maintaining the shape of the eye. If the circulation of this fluid is impeded, it can cause an increase in pressure leading to a condition known as glaucoma. This condition can significantly affect the optic nerve if the pressure becomes abnormally high. In addition to intraocular pressure, the human body also regulates spinal and skull pressures, bladder pressure, and pressures within the skeletal system. People over 40 should have their intraocular pressure tested regularly since they are at higher risk for developing glaucoma. Measurement of this pressure can involve force applied to the eye or a noncontact method using a puff of air to determine the necessary force to indent the eye.