Why is blue light utilized in applanation tonometry?

Blue light is utilized in applanation tonometry primarily to enhance visibility of the cornea. In this method of assessing intraocular pressure, clear visualization of the corneal surface is essential for accurate measurements. The blue light provides better contrast against the white sclera, making it easier for the practitioner to observe the indentation of the cornea caused by the tonometer. This enhanced visibility aids in more precise alignment and assessment, ultimately improving the accuracy of the intraocular pressure readings.