is how the lens looks when it's removed from the mold. The edges
can be trimmed with a utility knife to fit the brain. A dab of glue
holds it in place.
The top photo
shows a lens cast in a clear finish. Using clear plastic for a mold
gives this look.
photo shows a lens made with a frosted finish, molded from styrene.
I spray it with a clear coat to make it translucent. This is the
lens pictured in the brain below.
For both lenses,
I recommend backing with a piece of mylar to diffuse the light and
mask any imperfections.