An instrument used to measure intraocular pressure is:

A) gonioscope.
B) laser.
C) ophthalmoscope.
D) tonometer.

Tonometer

An instrument used to measure the pressure inside the eye, important for diagnosing and monitoring glaucoma.

Intraocular Pressure

The fluid pressure inside the eye, critical for maintaining eye shape and proper vision; abnormalities can indicate glaucoma.

Measure

To ascertain the size, amount, or degree of something typically using an instrument or device designed for that purpose.