US Patent 7963126 Glass fibers having improved durability

A glass fiber and a method of manufacturing a glass fiber for reinforcing a transparent composite matrix is disclosed. The glass fiber includes a first glass material having a first refractive index, a first modulus, and a first durability characteristic and a second glass material having a second refractive index, a second modulus, and second durability characteristic. The second durability characteristic is greater than the first durability characteristic. Durability characteristic is selected from the group comprising resistance to chemical attack, resistance to acid attack, resistance to fading from exposure to ultra-violet radiation, and resistance to mechanical abrasion.