by Joel Harrison
8. May 2011 18:11
Researchers and eye care practitioners tend to concentrate on lens material when they try to find contact lenses that would give their patients the highest comfort, but – as Ronald K. Watanabe, OD, FAAO, observes in his latest article in Contact Lenses Today – lens design may also be very important here.
According to Watanabe, the design of the edge of the lens is critical, regardless of whether we deal with soft contact lenses or GP ones. An edge with a gradual taper is the optimal design with respect to GP lenses; such lenses also require an appropriate edge lift, as when it is too high, it causes lid interaction and when it is too low, it may hurt the cornea.
In soft contact lenses, the issue of the design of the edge is more complex. They are, Watanabe writes, difficult to assess clinically, except for very flat or very tight edges. This difficulty, however, should be soon overcome, as new technologies are being developed.
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