<prompt> Tonography helps you to determineThe rate of formation of aqueousThe facility of outflow of aqueousThe levels of intraocular pressure at different times.None of the above  <response>: There are two similar terms.TonographyTonography 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. 