CLC OPHTHALMOMETER MEASURING TECHNIQUE

The CLC ophthalmometer measures the 
curvature of the cornea by reflecting mires 
(images) from the cornea and takes 
readings from two points on the corneal 
surface using a doubling technique 
(see How the Keratometer Works
-the ophthalmometer works by the same 
optical method ).  Since the measurement
 is made from just these two small points, 
the ophthalmometer only gives an 
approximation of the central curvature and 
does not give information about the whole 
surface. 

The separation of the two points 
on the cornea will vary with the 
corneal curvature.  For the 
average corneal curvature the 
separation is about 3.2 mm.