optically

This term is primarily used in technical, scientific, or medical contexts to describe how light behaves or how the eye perceives an image. It distinguishes between a physical change in an object and a change that occurs only in the way the object is seen. For example, an object might be optically distorted without being physically deformed.

In engineering and physics, it refers specifically to the application of optical laws, such as the design of lenses or fiber optics. It is rarely used in casual conversation, appearing instead in professional reports, technical specifications, or academic discussions regarding vision and light.