Keratometer measures September 2010 September 2012, March 2013 (e)
Ans. C: Curvature of cornea A keratometer, also known as a ophthalmometer, is a diagnostic instrument for measuring the curvature of the anterior surface of the cornea, paicularly for assessing the extent and axis of astigmatism. A keratometer uses the relationship between object size (0), image size (I), the distance between the reflective surface and the object (d), and the radius of the reflective surface (R). If three of these variables are known (or fixed), the fouh can be calculated using the formula R = 2dI/0
Thickness of cornea
Radius of cornea
Curvature of cornea
Depth of posterior chamber