**Core Concept**
Intraocular pressure (IOP) is a critical parameter in the diagnosis and management of glaucoma, a leading cause of irreversible blindness worldwide. Accurate measurement of IOP is essential to assess the risk of glaucomatous damage and monitor the effectiveness of treatment.

**Why the Correct Answer is Right**
The correct method for measuring IOP involves using a tonometer, which applies a gentle pressure to the cornea to assess the resistance to indentation. The Goldmann applanation tonometer (GAT) is considered the gold standard for IOP measurement due to its high accuracy and precision. It works by applanating (flattening) a small area of the cornea and measuring the force required to achieve this applanation. This method takes into account the corneal thickness and refractive error of the eye, making it a reliable and reproducible technique.

**Why Each Wrong Option is Incorrect**
**Option A:** Tonometers that use indentation principles, such as Schiotz tonometry, are less accurate than applanation tonometry and may be affected by corneal rigidity and thickness.
**Option B:** Digital tonometry, such as iCare or Rebound tonometry, may provide a quick and easy measurement but lacks the precision and accuracy of applanation tonometry.
**Option C:** Ophthalmodynamometry measures the blood pressure in the ophthalmic artery but does not directly measure IOP, making it an indirect and less reliable method.

**Clinical Pearl / High-Yield Fact**
Always use the Goldmann applanation tonometer (GAT) as the primary method for measuring IOP in clinical practice, as it provides the most accurate and reliable results.

**Correct Answer: C. Ophthalmodynamometry. Ophthalmodynamometry measures the blood pressure in the ophthalmic artery but does not directly measure IOP, making it an indirect and less reliable method.**