I have for the longest time wondered this. Three Makuta in Karda nui lost their eyesight when Matoro sacrificed his life to save Mata Nui. This forced them to carry a shadow matoran on their back in order to use their eyes through telepathy.
Why did they do so? Makuta are shapeshifters. Couldn’t they grow another set of eyes? Or absorb a matoran in order to have necessary energy to do so.
One of the kraata powers is healing. They can heal serious injuries on themselves and on other beings. I assume this would include regenerating missing limbs.
Also, Makuta are made of gaseous antidermis which lacks eyes. Biosector states antidermis heals up when it is within makuta armor. Not to mention How could an antidemis even become blinded when it was safely inside the makuta armor when the blinding light hit them.