Dr. Turner Waddell plowed his Volvo into Neil Colquhoun's Vauxhall Vectra on a highway near the village of Old Basing while driving at 70 mph, The Daily Telegraph reported Friday.
Colquhoun's vehicle spun onto the opposite side of the highway and burst into flames. He died of chest injuries sustained in the March 2011 incident.
After the incident, Waddell, who suffered from poor eyesight, was in the early stages of dementia and had been traveling the wrong way on the highway, told police his memory of the events leading to the collision were "hazy," but said he was "fine to drive" and did it most days.
"Undoubtedly, with his vision, he should not have been driving. It's fair to say the doctors who saw him did not tell him not to drive because they did not realize he was still driving," said prosecutor Daniel Sawyer.
Waddell, a retired physician, was given a nine-month suspended sentence and his driver's license was revoked for the rest of his life.
Judge Keith Cutler said: "If there is any message that should come from this it should be that the elderly and those that care for them -- their families and doctors -- should think very, very carefully about whether the elderly should still be able to drive on the road."
"There is sometimes a form of arrogance that one can carry on exercising a right to drive when that should not be done," Cutler said.