Manager Cecil Cooper said the first baseman did not notice a problem with his eye until he woke up and looked in the mirror.
Berkman, who left the game after pinch-hitting for reliever Dave Borkowski, told The Associated Press before the game that he had yet to see a doctor and did not know when he would return to the field. His eye did not appear to look badly swollen or infected.
"I'm having trouble seeing out of it," Berkman said, according to the Houston Chronicle. "It doesn't really hurt, it's just swollen. It waters up. I can't keep it from producing pus and what not."
Berkman was leading the majors with 210 total bases and a .669 slugging percentage entering play Sunday. He was third in the NL with a .350 average and ranked second in runs scored (74), hits (110) and doubles (28).
Berkman, who has 22 homers and 69 RBIs, has played in 86 of Houston's 88 games.
Information from The Associated Press was used in this report.