Two deaf twin brothers in Belgium were euthanized by their doctor after realizing they were going blind and would be unable to see each other ever again, their physician says.

The 45-year-old men, whose names have not been made public, were legally put to death by lethal injection at the Brussels University Hospital in Jette, on Dec. 14.

The men, who were born deaf, had a cup of coffee and said goodbye to other family members before walking into hospital room together to die, their doctor told Belgian television station RTL.

"They were very happy. It was a relief to see the end of their suffering," said Dr. David Dufour.

"They had a cup of coffee in the hall. It went well and a rich conversation. Then the separation from their parents and brother was very serene and beautiful," he said. "At the last there was a little wave of their hands and then they were gone,"

More than 1,000 people legally availed themselves of doctor-assisted deaths in Belgium in 2011, most of them were terminally ill cancer patients.

The brothers are unique in that their illness was not terminal. Belgian law, however, allows doctors to euthanize "suffering" patients who are both mentally sound, over 18 and want to die.

Belgian lawmakers are considering a law that would extend euthanasia to dementia patients and children, whose families and doctors consented.