The case suggested above by Dr. Drib is great. I've had one on my Oasis for almost a year now, and I've never considered taking it off. The case adds very little weight, but it makes the Oasis much nicer to hold. It makes the back of the Oasis feel very similar to the back of a Paperwhite. The case also creates a small lip on the front which protects the screen when putting the Oasis screen side down on a flat surface.
https://www.amazon.com/Young-Kindle-...=mr060-20&th=1