If the socket is in a fixture deep enought to keep it spaced away from the bulb, a sheet of vellum (paper) folded in "accordian pleats" for stiffness and additional scattering, placed between the bulb and the area to be illuminated makes a fairly effective "diffuser" to eliminate the glare from a clear bulb.

If the vellum blocks too much light, it can be made "more transparent" without losing the diffusing effect by soaking a bit of almost any clean oil into it before folding - but be sure to drain thoroughly. An ordinary (clothing) iron run over a piece of waxed paper turns it into a similarly effective material, or you can lay the waxed paper over (or under) the vellum and use the iron to transfer some of the wax to the vellum to increase the vellum transparency. The iron can also be used on an "oiled vellum," with a paper towel for backing, to wring out any excess oil.

For a fancier installation, your lumber yard probably has a variety of plastic "diffusing glasses" in sheets from which you can cut about any shape needed. Some of the glazing sheets (the acrylics) can even be bent with a little bit of heat, if it's done carefully; although the most common ones (polycarbonates - for scratch and breakage resistance) don't lend themselves to this without exotic (for home use) tooling.

There's no good reason to need to see the individual bulb(s) - from the outside - in an interior lighting fixture of reasonable quality. A functional diffuser is a really simple way of cutting the glare from a harsh bulb, and a minor bit of inventiveness usually can provide a way even for fixtures that omitted the feature.

John