Thermal injuries to ocular tissues causes a certain type of damage. If the cornea, the clear part is damaged, it turns unclear, usually white, like the white part. We can't see through white, so vision is affected. If it's a 'minor' thermal injury, the cells will recover and the clarity of the cornea will return.
If there is so much thermal injury that the iris is damaged, the lens will be damaged as well, and the cornea will most likely be the Major concern of the person, and the doctor.