Accurate intraocular pressure (IOP) monitoring is crucial in ophthalmology, especially for diagnosing and treating disorders like glaucoma. Applanation tonometry is one of the most used IOP measurement techniques, although it has drawbacks that can reduce effectiveness and patient comfort. But the introduction of the Tonopen has revolutionized how eye care professionals assess and manage IOP by providing portability, simplicity of use, and non-contact evaluation, improving patient care and producing better results.