It could happen any minute-an accidental bump or blow to your head or face.
And if you wear eyeglasses-either prescription glasses to correct vision, or sunglasses-it could mean injury to your eyes.
But now, requirements have been placed on manufacturers by the food and Drug Administration.
There are new impact resistant eyeglass lenses that will help protect you from such injury.
Impact resistance in eyeglasses does not mean the lenses are shatter-proof.
It does means that they can withstand moderately sharp blows and not shatter.
This means that a lens must pass the "drop-ball" test.
In this test a 5/8 inches steel ball weighing 0.56 ounces is dropped on each lens from a height of 50 inches.
This is the kind of force or weight involved in many accidental bumps or blows in the area of the eyes.
Every prescription lens and sun glass lens must now pass the drop-ball test after grinding and other finishing.
Manufacturers have many ways to make lenses impact-resistant.
They use heat or chemicals, impact-resistant material like plastics, or glass material thick enough to provide impact resistance.