Try this -- To change the size of the font:
1. From Idle mode, press Menu ➔ Settings ➔ Personalize ➔ Display settings ➔ and press the Select soft key or Ok.
2. From the Display settings menu, highlight Dialing display and press the Select soft key or Ok.
3. Select the Font size option and press the Select soft key or Ok.
4. Use the Left or Right Navigation key to select between: Small, Medium, or Large and press Save.