What is a disadvantage of randomly flattening spherical curves in lens design?

Randomly flattening spherical curves in lens design can indeed lead to reduced peripheral vision. This is primarily because when the curvature of the lens is altered without careful design considerations, the way light enters the lens can change. Spherical lenses are typically designed to maintain a particular profile to ensure that light rays are bent appropriately to reach the retina. If the curvature becomes excessively flat, this can cause light rays from the peripheral areas to focus incorrectly or even miss the retina altogether, resulting in blurred or distorted vision at the edges of the lens.

Maintaining the appropriate curvature is vital for ensuring that peripheral vision remains clear and functional. Therefore, while some may believe that flattening lenses could improve vision or comfort, it is essential for lens designers to consider the overall optical performance, including how changes to the lens shape can impact vision quality at various angles, especially in peripheral zones.