Which type of eyeglass lens does not have a visible line on the lens?

Progressive addition lenses (PAL) are designed to provide a seamless transition between different vision zones—distance, intermediate, and near—without any visible lines on the lens. This feature allows for a more natural visual experience as the wearer can shift their gaze smoothly through the lens without the abrupt changes that come from lined multifocal lenses. Single vision lenses, which correct for one field of vision (either near or far), also do not have any visible lines.

This makes the combination of PAL and single vision lenses the correct choice, as both types maintain a uniform appearance and do not disrupt the aesthetic of the eyewear. The absence of visible lines in these lenses enhances the wearer’s comfort and visual acuity across various distances.