The child, identified as Dhanush by news agency PTI, was moved to hospital on January 29 in Madurantakam, 86 km from Chennai.
As soon as he answered the cellphone, it exploded, leaving him with severe burns on his face, eyes and hand.
"The intensity of the blast not only damaged his right Cornea, it also ruptured the globe of his left eye, the right hand that was used by the boy to hold the phone suffered serious burns," said Dr Waheeda Nazir to PTI.
She added that he should be able to go home in about three weeks.
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