If you get a foreign object in your eye: Wash your hands with soap and water. Use an eyecup or a small, clean drinking glass positioned with its rim resting on the bone at the base of your eye socket. Fiberglass is a common material, a composite made of microscopic glass shards used primarily in insulation and construction. These tiny fibers, known as synthetic vitreous fibers, present an immediate hazard if they come into contact with the eye. Eyelashes, a fiber from your sweater, and even the smallest speck of dirt can feel like a boulder and bring a waterfall of tears. It's important to know the. Examine the affected eye closely to determine the number of fiberglass insulation fibers you're dealing with.