Having your phone that close to your eyes for any extended period of time is going to be absolutely painful. Unless you can link a small camera with live feed to screens that are designed to be used extremely close to your eyes (think google glass), I'd stray away from electronics and try another route. I know roxy roo used a door peep lens, like the wide angle lens you look through to see people outside of your door. That might be worth a shot!
If you are set on using your phone, why not juse glue in a cheap case designed to hold it? Simplementation and effective.