UV blocker found to have additional benefits

The UV blocker used in Johnson & Johnson Vision Care’s Acuvue contact lenses is reported to help protect a tear film component that can be taken into the lens during wear.

Sharing its findings from two studies at the Association for Research in Vision and Ophthalmology (ARVO) conference, the contact lens company explained that as well as being a UV blocker, Norbloc acted as an antioxidant and had a protective effect.

Principal scientist and leader of the scientific evidence team in global medical affairs at Johnson & Johnson Vision Care, Charles Scales, said: “This new research – through two different experimental models – showed that the same component that provides UV blocking also provided antioxidant protection.

“In these studies, Norbloc exhibited antioxidant properties greater than many known biologically significant antioxidants. This is important, new scientific information for eye care professionals given the heightened consumer interest in health and antioxidants.”

Researchers also observed that Norbloc provided a protective effect from oxidation of a tear film lipid, “which may support the comfort observed with Acuvue contact lenses,” the company said.

In one study, Norbloc’s antioxidant capacity was compared to 10 antioxidant compounds using oxygen radical absorbance capacity (ORAC). This process demonstrated its “very high” antioxidant capacity, which was higher than nine of the 10 comparison compounds.

In the second study, two silicone hydrogel lens formulations were prepared with and without Norbloc. Using an experimental lipid model, researchers examined the rate that the tear film lipid absorbed into a senofilcon A silicone hydrogel material oxidises or degrades. After exposure, the lens with Norbloc showed higher amounts of oxidative degradant A compared to the lens that did not contain Norbloc.