England bowler Stuart Broad says he is yet to get over the mental scars of being hit in the face by a Varun Aaron bouncer last August.
Broad, 28, needed hospital treatment after being struck during the fourth Test against India in Manchester.
He top-edged the ball through the grille of his helmet and was left with damage to his nose and two black eyes.
"I get nightmares still and I wake up thinking I have been hit in the face by a ball," he said.
"Even when I get tired I see balls flying at me. My jaw clicks from it and if I have two glasses of wine I have black eyes."
Broad has been working with a psychologist since his return and concedes the incident has affected his game.
"It knocked my confidence big time. Not for the next game - I felt fine going out to bat, nervous but fine," he said.
"But during my time out with the knee injury, I had nightmares about it.
"It probably has affected me more [than just the facial injuries]. It was a decent blow."
Broad has taken only two wickets in England's first four matches at the World Cup.