Aarish, 15, sits on a hospital bed in the central Indian state of Madhya Pradesh. A pair of dark glasses hides a painful injury in his left eye.
His cornea was damaged a week ago when an improvised firecracker device that he bought to celebrate the Diwali festival exploded near his face, causing him to lose vision in one eye. He has undergone emergency surgery and his doctor says only time will tell how much sight he can regain.
The teenager, who doesn't go to school, says he's most worried about missing work - his father works as a gardener and Aarish repairs televisions to supplement the family income. Child labour is illegal in India, but millions of children work. Indian law allows children above 14 years to work in some industries which are seen as non-hazardous.
Aarish is among hundreds of children and young adults from at least five states across northern India who have suffered serious eye injuries from using the same kind of device - called carbide guns - during Diwali.
The carbide gun, a rudimentary device, using calcium carbide in a plastic pipe, gives dramatic results - a loud blast that sounds like a gunshot, accompanied by fiery sparks. But the explosion is unpredictable and often delayed - officials told the BBC that many of the injuries occurred when children peeped inside the pipe to check just as the blast happened.
The sale and purchase of calcium carbide is regulated in India, but farmers and shopkeepers often use it to artificially ripen fruit. Police officials also say the crude guns are sometimes used to scare away animals from fields.
But many in India had not heard of these guns until last week, when a spate of injuries was reported after Diwali. Officials said these devices began flooding local markets in northern India after viral social media videos showed them being used as firecrackers.
More than 100 cases of carbide gun-related eye injuries have been reported in Madhya Pradesh's Bhopal district alone, with at least 15 requiring surgery. Another 100 cases have been reported from three other districts.
In Bihar state, 170 cases have been reported, with 40 requiring surgery, says Dr Bibhuti Prassan Sinha, who heads the Regional Institute of Ophthalmology in Patna city. The actual numbers are likely to be higher, he added.
Cases have also been reported from the states of Chhattisgarh, Jharkhand and Uttar Pradesh, as well as capital Delhi. Some states, including Madhya Pradesh, have now banned the use of carbide guns as firecrackers and several sellers have been arrested.
Kavitha Kumar, head of ophthalmology at Hamidia Hospital in Bhopal, says that patients have been coming in with mild, moderate and severe eye injuries.
In milder cases, skin on the eye and around it has sustained chemical injuries and thermal burns. In moderate cases, chemical particulate matter has caused mild damage to the cornea and in severe cases, there's extensive damage to the cornea, causing temporary vision loss. With surgery, the patient may be able to regain their sight over time, she says.
Some doctors told the BBC that they were shocked by the severity of the injuries. Dr Aditi Dubey from Hamidia Hospital said that she had never seen chemical injuries caused by Diwali firecrackers and had to research what carbide guns were.
Many patients said that they bought the gun after seeing it on Instagram Reels and YouTube videos. An attractive aspect was the price - at 150-200 rupees ($1.70-$2; £1.28-£1.70) a piece, it was a relatively cheap firecracker that promised to make a big impact.
A search for the term carbide gun on Instagram and YouTube throws up dozens of videos of young people making and using these devices, often accompanied by rap music.
Dr Sinha told the BBC that one of his patients was an engineering student who made the gun at home after watching such videos. He's currently being treated after losing vision in one of his eyes.
Calcium carbide is a regulated substance in India - its possession, use and manufacturing are controlled by law because of its harmful effects and potential for abuse.
When it comes in contact with water, it produces acetylene gas, which is highly flammable and has damaging properties on health.
Under the Calcium Carbide Rules, 1987, a licence is needed for its sale, purchase and storage - but only for quantities above 200kg.
A government official in Bhopal who didn't want to be named told the BBC that calcium carbide is still widely used to artificially ripen fruit despite a federal ban as it contains traces of poisonous substances.
Harinarayanachari Mishra, Police Commissioner of Bhopal, told the BBC that carbide guns are also used in northern India during wedding festivities and by farmers to drive away monkeys.
Dr Partha Biswas, president of the All India Ophthalmological Society, says carbide guns should be banned urgently.
It's a national problem. And the seriousness of these incidents shouldn't be minimised as mere accidents that took place during the Diwali festival, he says.
He adds that there's potential for these guns to be used as firecrackers during other festivals and events, like when India wins a cricket match or during New Year.
These crude 'carbide bombs' or 'carbide guns' can cause permanent blindness, disfigurement and disability, he says, demanding a nationwide crackdown on manufacturers and sellers of the guns as well as more control over the supply chain of calcium carbide.
Back at Hamidia Hospital, Alzain, whose left eye was operated on after he lost his vision, sits inside the tight embrace of his mother. The seven-year-old had pestered his uncle to buy the gun after watching videos on YouTube.
Alzain's worried mother, Afreen, hasn't left his bedside since he was admitted a week ago.
I'm scared for his future, she says. I hope he's able to see again.
