Easy peasy!!
As already quoted, you must judge the exit time for a vehicle, plus the other test is to keep two vehicles, each on a separate road from bashing into the kerbs. Easier than it sounds!
The eye test has no alphabet, just open ended squares. You have to indicate which is the open end. They diminish in size but quite simple.
Lastly, a blood pressure check and in 2007, I paid 15 Euro.
The renewal lasts for two years, which means mine is due again shortly!!
Oh, as I am a Jubilado, the licence is free and can now be ordered by Correo, I believe, rather than visiting the Trafico.