Why is it important to consider frame size when fitting lenses?

Considering frame size when fitting lenses is crucial for several reasons, with one of the primary concerns being ensuring proper optical alignment and comfort. When lenses are positioned in a frame that fits appropriately, the optical centers of the lenses align with the wearer's pupils. This alignment is essential because it allows for optimal visual performance, reducing distortions and providing clearer vision. If the frame is too large or too small, it can lead to misalignment, resulting in discomfort, eyestrain, and a decrease in visual clarity.

Additionally, an appropriately sized frame enhances the overall comfort of the eyeglasses. A well-fitted frame will not exert undue pressure on the wearer's nose or ears and will help maintain a secure fit, preventing the glasses from sliding down or causing discomfort during wear. Therefore, frame size directly influences both the functionality and comfort of the eyewear, making it a key aspect of the fitting process.