Thomas Cadman was locked up for 12 months over the collision in which the victim suffered a broken pelvis, a broken leg and spinal injuries.
Cadman was almost twice the drink drive limit the morning after a drinking binge as he watched a football match.
Leeds Crown Court was told the incident happened when he veered into the wrong carriageway on Manchester Road, Huddersfield, as he adjusted his headlights in heavy fog.
Cadman's Mercedes van crashed head-on into an oncoming car being driven by a single mum.
The primary school teacher had to undergo surgery after suffering serious injuries.
Andrea Parnham, prosecuting, said the woman continues to suffer pain and receives physiotherapy almost a year after the incident, which happened on December 16 last year.
Cadman, of Rockingham Street, Fitzwilliam, near Wakefield, pleaded guilty to causing serious injury by dangerous driving.
Phillip Howard, mitigating, said Cadman had been driving his work's van at the time of the incident.
He said the collision occurred at the moment Cadman took his eyes off the road to adjust his headlights.
Mr Howard said: "The steering in the vehicle is very sensitive and as he turned away he caused the vehicle to veer into the line of oncoming traffic.
"It was something that happened momentarily and had devastating consequences for the complainant in this case."
Mr Howard said Cadman stayed at the scene of the collision to help the victim and identified himself to police when they arrived.
Cadman suffered chest injuries during the collision.
Mr Howard said Cadman lost his employment as a result of his convictions but had found a new job in traffic management.
The lawyer told the court Cadman's work involves conducting traffic flows when problems occur on the roads.
He said the 26-year-old lived with his partner and they have a child together.
Jailing Cadman, Judge Geoffrey Marson, QC, said: "The fact that you were almost twice the legal limit must have been a significant causative factor of you crossing on to the wrong side of the road.
"Those who drink and are over the limit and drive dangerously and cause injuries as serious as this must immediately go to prison.
"There has to be an element of deterrent."