Studying the solution

As contact lens materials and solution formulations become ever more complex, the compatibility of these products with the eye and with each other is an area of growing research interest.

A paper in the January issue of Eye & Contact Lens by researchers at the University of Waterloo in Canada looked at the interaction of benzalkonium chloride (BAK) with silicone hydrogel and conventional hydrogel lenses.1

Four lens types - Focus Monthly (vifilcon A), Focus Night & Day (lotrafilcon A), Acuvue Advance (galyfilcon A) and Surevue (etafilcon A) - were soaked for 24 hours in various concentrations of BAK. After 24 hours, the lenses were washed and then incubated in a balanced salt solution for seven days.