Guo Bin rests at Shanxi Eye Hospital in Taiyuan, Sept 2, 2013. [Photo/Xinhua]

The police said the criminal motive of Zhang Huiying may not be known as she had died.

The public has called for more details from the police to disperse the doubts over the case.

The boy's tragic experience led to national concern. As of Wednesday, his family had received one million yuan ($162,085) in donations, according to media reports.

The boy's eyelids have healed and the hospital will implant a pair of artificial eyes (ocular prosthesis) in a month's time, Jia Yading, director of Shanxi Ophthalmic Hospital told Xinhua on Wednesday.

"The artificial eyes cannot restore his sight," Jia said, who is also the head of the therapeutic team responsible for Guo's treatment.

All his medical expenses will be exempted by the hospital.

Hong Kong-based eye expert Dennis Lam said earlier his team would provide free treatment to the boy.

Lam told Xinhua on Wednesday that the boy is likely to restore partial sight within five to ten years thanks to electronic eye technology.

Lam is still waiting for consent from the child's parents to bring Guo to his eye hospital.

Meanwhile, Taiyuan Deaf-mutes School based in the provincial capital of Taiyuan announced on Wednesday it will offer the boy free education when he is able to go to school.