What is the significance of using a blue filter in applanation tonometry?

Using a blue filter in applanation tonometry is crucial for enhancing visibility, particularly when assessing the levels of intraocular pressure. Applanation tonometry requires clear visualization of the cornea to ensure accurate readings, and the blue filter plays a significant role in this process.

The filter allows practitioners to observe the fluorescein dye that is used in conjunction with the tonometry procedure, making it appear more vibrant against the natural tissue of the eye. This heightened contrast facilitates a clearer view of the area being assessed.

While other factors, such as glare reduction and overall illumination of the cornea, contribute to the ease of the procedure, the primary advantage of the blue filter lies in its ability to improve visibility of the fluorescein, thus confirming the quality of the examination and aiding in the achievement of reliable measurements.