OK, first, the penalties for being blind:
The character cannot see. He takes a -2 penalty to Armor Class, loses his Dexterity bonus to AC (if any), moves at half speed, and takes a -4 penalty on Search checks and on most Strength- and Dexterity-based skill checks. All checks and activities that rely on vision (such as reading and Spot checks) automatically fail. All opponents are considered to have total concealment (50% miss chance) to the blinded character. Characters who remain blinded for a long time grow accustomed to these drawbacks and can overcome some of them.
That's some big penalties, and in particular note that he never has line of sight to any target, so all ranged spells automatically fail, but only agree to give him something in return if he agrees to play a character who is
incurably blind, that is 'remove blindness' or 'regenerate' does him no good.
Suitable compensation might be to give him Skill Focus(Listen) and Blindfighting for free. In addition, he recieves a +2 circumstance bonus on all Perform checks in societies that are basically good aligned, as most good hearted people will be especially impressed by any talents he's displays having overcome such a hardship. He's also immune to any attack which effects vision, which in the long run is a pretty good thing. If you think that is too much, you might want to talk to your character about either dropping the free Skill Focus or else taking a small penalty on all saves vs. attacks with the sonic descriptor.
He'll still probably need to bump up WIS to 19 as soon as possible, in order to take Blindsight, 5' radius to overcome a good portion of the problems with being blind. Getting Blindsight, 5' radius means that he's not flatfooted when in melee, and opponents in melee don't have total concealment, he wouldn't have a -4 penalty on strength and dex based skill checks, and he'd be able to move his full speed and even Run in sufficiently unobstructed areas (not necessarily in a maze of twisty passages for example). He still would be effectively flat footed against missile attacks, but with enough ranks in Listen he'll at least be able to pinpoint where those attacks are coming from.
I would not advise allowing the player to overcome the difficulties with being blind above and beyond the free compensation you are giving except in special 'safe' circumstances. For example, the long term blind character can move at full speed
but only in areas in which he is intimately familiar. The long term blind character gets no penalty on swim checks
but only in calm water.