Canadian drugmaker Valeant Pharmaceuticals said Monday that it will pay $8.7 billion to buy Bausch + Lomb, one of the world’s best-known makers of contact lenses, in a massive expansion of Valeant’s smaller ophthalmology business.

Valeant said the cash deal will help it capitalize on increasing demand for contact lenses and other products because of aging populations, growing demand in emerging markets and increasing rates of diabetes. Complications of the complex blood sugar disorder can damage the eyes over time.