Final answer:
Minus lenses, such as those for nearsighted individuals, are diverging lenses that are thinnest in the center. The larger the eyewire opening of the frame, the thinner the edges of the lens can be, which affects the overall lens shape and comfort.
Step-by-step explanation:
For minus lenses, such as those used in eyeglasses for nearsighted people, the larger the eye wire opening, the thinner the lenses can be made at the edges. Minus lenses are often made with negative power, indicating they are diverging (or concave) lenses. A diverging lens tends to be thinnest in the center, and as the size of the eye wire opening increases, the edge thickness can be reduced, maintaining the lens's corrective power while potentially improving comfort and aesthetic appeal. Nearsightedness or myopia means that distant objects are blurred because the eye focuses light in front of the retina.
Using a diverging lens helps to correct this by spreading the light out more before it enters the eye, allowing it to focus on the retina. The power of eyeglass lenses for nearsighted individuals is measured in negative diopters, corresponding to the necessary degree of light divergence to provide clear vision.When designing eyeglasses, the relationship between lens power, lens shape, and frame size is crucial for ensuring effective vision correction and user comfort. Therefore, the size of the eyewire—the frame that holds the lens—must be taken into account when designing and fitting corrective lenses.