by Joel Harrison
7. July 2011 10:09
Many people believe that silicone hydrogel contact lenses are more comfortable than hydrogel ones, which is supported by the results of some clinical trials and studies (during which it was discovered that patients, after replacing hydrogel lenses with silicone hydrogel ones, felt more comfortable and wore their lenses for longer periods). However, according to Ronald K. Watanabe, OD, FAAO, one should take other factors into consideration, such as surface hydration, lubricity or design.
It is said that silicone hydrogel lenses improve end-of-day comfort because of their higher oxygen permeability, but some researchers think that the lower oxygen permeability of hydrogel lenses has a similar effect by “numbing” the eye.
Moreover, a recently published study showed – in addition to confirming previous research results with respect to the proportion of contact lens users suffering from dry eye symptoms (30%) – that contact lens material did not have an impact on the occurrence and severity of dry eye.
In his article, Dr Watanabe comments on these results, stating that the lack of difference between the materials may be connected with the fact that both types have their advantages related to patient comfort and, consequently, doctors should consider each case separately.
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