What is Norbloc?
Norbloc is a UV blocker used by Johnson & Johnson Vision in most of the ACUVUE brand contact lenses. Norbloc (7966) is manufactured by Edison, NJ-based Pharnorcia Inc., a company specializing in the production of high-purity optical-grade materials for soft contact lenses and intraocular lenses (IOLs). Norbloc is registered in the CAS Registry database with the registration number 96478-09-0 - it's molecular formula is C18H17N3O3.
A recent study by Johnson & Johnson Vision has found that the UV blocker Norbloc - used in many ACUVUE product - has an additional benefit besides the filtering of harmful UVA and UVB rays. It provides antioxidant protection with an ORAC score four times higher than Vitamin E. ORAC stands for Oxygen Radical Absorbance Capacity. Antioxidants play an important role in the protective mechanisms preventing oxidative injury of the cornea and damage of the inner parts of the eye caused by UV rays and by a reactive oxygen imbalance.
In another study, Norbloc also showed statistically lower amounts of oxidation of a tear film lipid compared to lenses that did not contain Norbloc. This may help with the wearing comfort observed with ACUVUE lenses.
U.S. National Library of Medicine - PubChem - Chemical Information
- C18H17N3O3 - Chemical Information
UV Rays, the prooxidant/antioxidant imbalance in the cornea and oxidative eye damage
- Cejková J1, Stípek S, Crkovská J, Ardan T, Pláteník J, Cejka C, Midelfart A.
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague - Feb 2003
Popular ACUVUE Lenses with Norbloc UV Blocker