Question:
Has anyone had difficulties finding a suitable replacement for this lens?
i have been wearing this contact lens for almost 20 years and
it fit perfectly. None of the modern high-water lenses are stable enough or
fit as well. Have tried these makes, in order of closest fit:
J&J accuvue, B&L optima38, Ocular Science, CIBA daily wear.
The U4 is (was) the only lens that fit without making its presence known.
Why did they stop making this lens??? Does this have to do with making money
on disposables?? If so, shame in this industry.
Answer:
The U4 was(is) a 38% water polymacon, large 14.5 diameter lens made by
the old "spincast" process. The liquid polymer would be introduced
into a spinning mold. In this manner, the edges could be feathered to
an extraordinary degree of thinness. The lens was extremely
conforming to the eye. This process is now obsolete, as most lenses
are now made by injection molding.
I have never been able to find an identical substitute. However,
Ocular Sciences, which purchased American Hydron, which held the
original soft lens patent invented by Otto Wichterle, does still
manufacture a line of polymacon lenses. Somebody has mentioned the
Z6, but I would also add the EdgeIII ProActive. Unfortunately,
neither of these is available in 14.5 diameter.
Other lenses to consider include the Ciba Focus Monthly or One-Two
Week, but not the Night and Day. The edges are similarly thin and the
lenses do not exhibit much movement on the eye. So, if you are
looking for a stable lens that doesn't move much, those Ciba lenses
might be just right for you. If you want to try a modern lens using
an advanced polymer, you might try the Proclear Compatible. However,
I think you might find that it tends to show more translational
movement than the Ciba lenses.
