Distraught about going blind, 45-year-old deaf twin brothers from Belgium chose to be euthanized because they couldn't bear not to see one another, according to reports from Flanders.

Marc and Eddy Verbessem of Putte died Dec. 14 by lethal injection at Brussels University Hospital. Voluntary euthanasia has been legal in Belgium since September 2002.

The doctor who presided over the euthanasia described the twins as being "very happy."

"It was a relief to see the end of their suffering," David Dufour told Germany's RTL TV network. "They had a cup of coffee in the hall, it went well, and a rich conversation. The separation from their parents and brother was very serene and beautiful. At the last, there was a little wave of their hands, and then they were gone."

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The twins, who were born deaf, had spent their entire lives together. Both were cobblers, and they never married or had children.

"They lived together, did their own cooking and cleaning. You could eat off the floor. Blindness would have made them completely dependent," their older brother, Dirk, told the London Telegraph. "They did not want to be in an institution.

"Their great fear was that they would no longer be able to see each other," he said. "That was for my brothers unbearable."

He said he and their parents tried to talk them out of it, but they were persuaded to let them die as they wanted.

The brothers' hospital refused their desire to end their lives, because doctors did not accept that they were suffering unbearable pain, one of the major requirements, the Telegraph says.

Here's the law and researchers' summary of what it requires:

To make a legitimate euthanasia request, the patient must be an adult, must be conscious and legally competent at the moment of making the request, and must be in a condition of constant and unbearable physical or psychological suffering resulting from a serious and incurable disorder caused by illness or accident, for which medical treatment is futile and there is no possibility of improvement.

The physician decides whether the disorder is incurable based on the actual state of medicine, and the patient alone determines whether suffering is constant and unbearable. The physician must have several conversations with the patient in which he ascertains whether the patient experiences his/her suffering as constant and unbearable.

The physician must inform the patient about their medical condition, prospects, and possible alternative treatments, including palliative care. He must consult another independent physician about the serious and incurable character of the condition. This physician does not need to be a palliative care specialist.

From 2002 through the end of 2011, more than 5,500 Belgians chose euthanasia, the European Institute of Bioethics reported last April. For 2011, the most recent figures, 1,133 people, mostly suffering from terminal cancer, chose to end their lives.

In 9 per cent of declared cases of euthanasia, death was not imagined in the very short term. The most often declared illnesses mentioned to justify this type of request are first and foremost neuropsychiatric diseases, followed by degenerative neuromuscular diseases and a combination of non-fatal "multiple pathologies."

In 91 per cent of requests, death was considered as expected in the short term and among these requests, 75 out of 100 concerned pain relating to cancer while 5 out of 100 requests related to pain due to a neuropsychiatric disease, a non-degenerative neuromuscular disease (following an accident...) or a combination of multiple pathologies.

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Days after the brothers' deaths, the ruling Socialists in Belgium's Parliament tabled a proposal to expand euthanasia to adults suffering from dementia or Alzheimer's and to children 17 and younger, an idea first considered in 2005.

Calling legal euthanasia a "slippery slope," Catholic Online declares, "It is only a matter of time before we report the story of the first child euthanized in Belgium," which is predominantly Catholic.