Blindness: Do the eyes react to light?

With that sort of damage (I assume that there were chemical burns that ruined the eyes) probably not much reaction . If the character could see light and dark, and just couldn't focus, then the eyes would react. It depends on the amount of damage and what part of the eye was damaged. It's up to you, but make the damage appropriate to the result.

You'll have to think about what you want. I think that most of the time, the blinding is actual mechanical damage to the eye from the debris of the explosion (lens disrupted, vitreous and aquaeous humor lost, retina, optic nerve, or blood supply lacerated) than the actual chemical corroding the eye from cornea back to the retina.

Now, if you just have a big splash of acid in the eyes, the cornea is eroded back to the lens. If the lens gets clouded, then it's like instant cataracts. The eye will still react to light, but there will be no focussing power. If you're driving shards of glass into the eye, it's probably beyond help and will have to get enucleated.