Abrasion resistant coatings for unsaturated polymeric substrates

A process for producing an abrasion-resistant, adherent, optically clear coating on an ophthalmic lens formed from diethylene glycol bis(allyl carbonate), comprising:

• a. forming a coating solution containing from about 25 to about 75 percent by weight of a hydrolyzed vinyltri(lower alkoxy)silane in a water-miscible, volatile, organic solvent, said coating solution also containing from about 1 to about 20 percent by weight of an amino (C.sub.1 -C.sub.8 alkyl)tri(C.sub.1 -C.sub.3)alkoxysilane and from about 0.1 to about 0.5 parts of a stabilizing weak acid having a pKa of between about 5.times.10.sup.-3 and about 5.times.10.sup.-5 per part of amino(C.sub.1 -C.sub.8 alkyl) tri(C.sub.1 -C.sub.3)alkoxysilane, by weight;
• b. applying a coating of said solution to a clean surface of said lens;
• c. dehydrating the coated lens at a temperature of between about 70.degree. C. and 100.degree. C;
• and,
• d. subsequently irradiating the dehydrated, coated lens with ultraviolet light until an adherent, optically clear coating having significantly improved abrasion-resistance is formed.