This lamp is designed for an LED "puck" light. Battery operated lights are about $4 each; simply do a web search for "LED puck light" to find several sources. This blog page tells where you can get wall powered lights that are brighter and that work very well: http://birkbinnard.com/blog/wall-powered-led-lights/.
This light uses the same basic geometry as https://pinshape.com/items/387..., but the sections forming the sides are flipped 180 degrees so they are convex instead of concave. For this print I used 2 different filaments: regular yellow for the bottom and then transparent yellow for the top. The transparent lets a lot more light out, but it also results in more fine stringing. This print took 14 hours 3 minutes using a layer height of 0.200 mm. and print speed of 100 mm/sec.