Is it normal for half-frame glasses to have a line etched around the lens?

[Zuri]

I just bought a pair of half frame glasses. There is an etched line around the lens border, is this normal?

[Chana]

Yes. It is quite normal. It is a nylon string that is used to keep the lens in the frame. Some lenses may use screws to hold the lens in and others need the nylon.

[Ingrid]

The lenses have to be edged in that way in order to keep them in the frame. If you look carefully you will find what looks almost like fishing line in the groove. That is how the lens is kept in the frame. It is quite normal.