In a preceding publication,1 the calculated C value of tonography was shown to be significantly affected by whether the eye, during tonography, was in the accommodated or relaxed state. The C values obtained during accommodation were significantly larger. Furthermore, attentive fixation of the "fixation-light" of the slit lamp for 4 min. was shown to be an adequate stimulus of accommodation: The chamber angle depth was increased and the Schiøtz pressure reading was reduced after that procedure.
The applanation tonometer of Goldmann provides a measure of the intraocular pressure, which is independent of the coefficient of ocular rigidity of the eye. In this procedure the fixation-light of the slit lamp is used to help maintain the eye in a constant position. Using this technique, Goldmann described a progressive reduction in intraocular pressure on repeated applanation tonometry. The reduction continued over a period of minutes until a steady state was attained
ARMALY MF, RUBIN ML. Accommodation and Applanation Tonometry. Arch Ophthalmol. 1961;65(3):415-423. doi:10.1001/archopht.1961.01840020417016