Tonometry is a field of research that focuses on measuring the intraocular pressure within the eye. This is important for diagnosing and monitoring conditions such as glaucoma, as elevated intraocular pressure can damage the optic nerve and lead to vision loss. Tonometry techniques include applanation tonometry, air puff tonometry, and non-contact tonometry. Researchers in this area work to improve the accuracy and reliability of these techniques, as well as explore new methods for measuring intraocular pressure.