Increased intraocular tension can be diagnosed by
Tonometer
Pachymeter
Placido's disc
Keratometer
The intraocular pressure (IOP) is measured with the help of an instrument called tonometer. Two basic types of tonometers available are: indentation and applanation. Indentation (impression) tonometry is based on the fundamental fact that a plunger will indent a soft eye more than a hard eye. The concept of applanation tonometry was introduced by Goldmann is 1954. It is based on Imbe- Fick law which states that the pressure inside a sphere (P) is equal to the force (W) required to flatten its surface divided by the area of flattening (A); i.e., P = W/A. Reference: AK khurana 7th edition
Anatomy, Development and clinical examination