The power of sunglasses (A) is typically measured at 0 diopters. Unlike corrective lenses, which are prescribed to correct vision impairments by refracting light, sunglasses primarily function to reduce glare and protect the eyes from harmful ultraviolet (UV) rays. The term “0 diopters” indicates that sunglasses do not alter the focus of light entering the eye; instead, they act as filters that selectively block certain wavelengths of light, particularly UV radiation and intense sunlight, while allowing visible light to pass through with minimal distortion. This feature enhances visual comfort and protects against eye strain and potential damage from UV exposure. Sunglasses are essential accessories for outdoor activities, driving, and general eye protection against environmental factors. Understanding their power in terms of diopters emphasizes their function as protective eyewear rather than corrective devices, underscoring their role in maintaining eye health and comfort in various light conditions.