How can one eccentricity fit most corneas ?
Conforma-K corneal lenses are available in a .65 eccentricity (peripheral flattening factor). However, using the same eccentricity value but changing the base curve value also changes the peripheral flattening since the base curve denotes the magnitude or size of the ellipse (hence, a steeper base curve will have a slightly steeper periphery and, conversely, a flatter base curve will have a flatter periphery). The two ellipses have the same eccentricity and are identical in shape, one is twice the size (linear dimension) of the other. The magnitude of the larger, given by r (base curve radius) is twice that of the smaller. Note how a change in base curve or overall lens size will affect peripheral fit. Conforma-K lenses with .65 eccentricity allows the ens to be fitted appreciably steeper for better entration while the less curved periphery is directed in a more downward, long, cone-like direction, thus paralleling the anomalous cornea. Controlled Edge Lift The Conform-A-Spheric will h
