Soft Contacts and astigmatism

What is the maximum range of astigmatism that can be masked by a soft lens
before a toric is needed?

In general do certain spherical soft lenses provide better vision for people
with astigmatism than others? Is a stiffer lens better, or a thinner/softer
lens that draps better? I guess at the end of the day the best lens is what
provides the best fit.

Is the way a lens drapes the cornea the reason why different powers are
needed between lens designs. i.e using the Ciba calculator different
strength are required between Ciba Dallies and Ciba N&D etc.

 

Objectively, about .5D for the thicker or more rigid plastics, zero for
the most. Subjectively, using aspheric optics, about 1D horiz, .75D
vert.

See above.

Yes. If the lens gets coated with debris or dehydrates or decenters,
the vision, and comfort, suffer.

Exactly. And using a "lens predictor" is only a starting point. It's
best to measure the effective lens power on the eye, especially when
dealing with a little astigmatism and with higher powers.

--LB

--
Dr. Larry Bickford, O.D.
Family Practice Eye Health & Vision Care

The Eyecare Connection
http://www.eyecarecontacts.com
larrydoc at eye-care-contacts dot com (remove -)

 

What is the maximum range of astigmatism that can be masked by a soft

In terms of monthly replacement or extended wear what lenses tend to offer a
better performace for masking astigmatism? (i.e Proclear, Acuvue, Surevue
etc). Is there a list of which lenses are aspheric anywhere?