COMPUTERIZED VIDEOKERATOSCOPES

Limitations and Sources of Error: Patient Fixation Errors

The error that occurs when the apex of the cornea is significantly 
decentered from the line of sight can be large.  A common example 
is keratoconic patients where the apex of the cornea is often 
significantly decentered.  The dioptric value of the apex can be off by 10 diopters or more.