Smartphone for 63 year old tech unsavvy father

Here's the story. I gave my father a Sony Ericsson TM506 about two years ago. His first cell ever, and it's practically changed his life. But the phone is old and... bad. I promised I'd get him a smartphone cause and he is very interested in them.

His specs:

- old, poor eyesight and definitely poor hearing on one side

- Yeti-class steel-worker manhands

- doesn't know a damn thing about technology

- barely speaks English

Phone specs (tentative):

- 4.5" screen or so (4" would be too small, 5" too big)

- needs to have a bright display that is highly readable outdoors

- needs to last 2 days on battery where usage is mostly phone calls and no data

- needs to be durable as he might toss it around his car or shove it in pocket with keys

- does not need to have uber specs or camera (I'd be amazed if he even figured out how to use it), but should be a dual core at least

- needs to have clear and loud call quality

- buying it full price, shouldn't end up costing me more than what a galaxy nexus does now

The GNex would be a great fit if the screen weren't so dim outdoors. I'd give him my Nexus S when I upgrade, but the same issue applies - and the display is even smaller.

Any general tips of how to simplify it for him are also appreciated.