Tonography helps you to determine –
There are two similar terms.

Tonography

Tonography is a non-invasive technique for determining the facility of aqueous outflow (C-value).
Facility of aqueous outflow is estimated by placing schiotz tonometer on the eye for 4 minutes.
Beside tonography, other methods to measure the facility of aqueous outflow (C-value) are perfusion method and suction cup method.
The average C-value is 0.28 ± 0.05 1/ min / mmHg. Most glaucoma patients have C-value less than 0.17.

Tonometery 

Tonometry is the assessment of the intraocular pressure of the eye.
Therefore, it is used in the diagnosis of glaucoma and for monitoring the treatment response in glaucoma.
The rate of formation of aqueous
The facility of outflow of aqueous
The levels of intraocular pressure at different times.
None of the above