A British teenager who had been a “fussy eater” since elementary school lost his vision and suffered significant hearing loss due to his yearslong diet of junk food, according to a case report published Monday.

When the boy was 14, he complained to his family doctor of tiredness. “He was a ‘fussy eater’ but was otherwise well and took no medications,” said the report published in the Annals of Internal Medicine. The doctor gave him vitamin B12 injections and advice on his diet.

By age 15, the teen began to lose his hearing and was referred to an ear, nose and throat specialist. Shortly after, he developed problems with his vision.

The teen’s vision continued to worsen over the next two years, and by age 17, his visual acuity had declined to 20/200, which is considered legally blind in both the U.K. and the U.S.

He was found to have a problem with his optic nerve, but tests didn’t point to an obvious cause.

When doctors investigated the teen’s habits and nutrition, he denied use of alcohol, tobacco or drugs, says the report by the boy’s doctors in Bristol, England.

“However, the patient confessed that, since elementary school, he would not eat certain textures of food,” the authors wrote. “He had a daily portion of fries from the local fish and chip shop and snacked on Pringles, white bread, processed ham slices and sausages.”

Nutritional deficiencies can contribute to vision and hearing problems, but in developed countries, “purely dietary causes” for such vision problems are rare, the authors wrote. In the teen’s case, nutritional deficiencies in several essential vitamins and minerals, including B vitamins and copper, probably played a role in his vision and hearing loss.

He was given nutritional supplements, and his vision stopped getting worse, though it didn’t improve.

The doctors also referred the teen to mental health services, concluding that his dietary habits constituted an eating disorder. “‘Fussy eating’ that is restricted to junk foods and causes multiple nutritional deficiencies is an eating disorder,'” the report says.

Optic nerve damage from poor nutrition “is potentially reversible if caught early. If left untreated, it leads to permanent blindness.”