When using the fluorescent bulb method to inspect a gas permeable lens, what pattern should be observed in a well-blended bevel?

When using the fluorescent bulb method to inspect a gas permeable lens, observing a J-shaped or ski pattern indicates that the lens bevel is well-blended. This particular pattern signifies that the lens has been polished adequately, with a smooth transition along the edges.

The J-shaped pattern reflects an area where the light reflects off the bevel correctly, showing a gradual blending without abrupt transitions. This is crucial for gas permeable lenses, as a smooth edge reduces the risk of discomfort to the wearer and aids in maintaining appropriate tear film stability.

The other patterns mentioned, such as straight lines, zigzags, or wave-like shapes, typically indicate some issues with the bevel’s finishing or alignment. These irregularities can lead to potential discomfort or poor lens performance, which is why the presence of the J-shaped or ski pattern is a strong indicator of a properly crafted lens.