______ is used to measure the pressure inside the eyes of a person.

Tonometer

The correct answer is option 4. Tonometer.

The device used to measure the pressure inside the eyes of a person is called Tonometer.

A tonometer is a medical instrument used to measure intraocular pressure, which is the pressure inside the eye. Elevated intraocular pressure can be a sign of glaucoma, a group of eye conditions that can lead to vision loss if left untreated. There are several types of tonometers, including applanation tonometers, non-contact tonometers, and indentation tonometers, each with its own method of measuring intraocular pressure. Regular measurement of intraocular pressure is an essential part of eye examinations, especially for individuals at risk of glaucoma.