Period Costs. Period costs are expenses that are easier to attribute to times and accounting periods than actual production processes or finished goods. Typically, managerial accountant want to classify expenses in categories that can improve operations. Manufactures tend to focus on functional classifications.
The amber color of these impact-resistant polycarbonate lenses block short-wavelength blue light and 100% of ultraviolet (UV) light, thus providing additional protection against cataract formation and the development of macular degeneration, while increasing contrast on both sunny and bright hazy days.
Always choose polarized sunglasses that block out 99 - 100% of UVA and UVB radiation to ensure you're protected. Sunglasses that do not provide UV protection can cause more damage to your pupils because they dilate when the light is blocked, exposing your eyes to more harmful rays than without sunglasses.