Hamilton wore new specially ordered sunglasses for the first time this season when the Rangers played the Los Angeles Angels at Angels Stadium Thursday afternoon in the rubber match of a three-game series between the contenders in the American League West.
However, his struggles under the sun continued with an 0-for-3 performance in the Rangers' 1-0 loss to the Angels. He twice grounded out with a runner on first.
After wearing sunglasses for his first three at-bats, he ditched them for his final plate appearance.
Hamilton kept a sense of humor about his struggles, saying maybe he's squinting too much.
"The less your eyes open the less you can see," Hamilton said. "Is that a Yogi-ism?"
After Wednesday night's 9-8 loss, in which Hamilton went 2-for-5 with an RBI, he used eye drops and lid scrubs designed to wipe away sweat that can make its way to the eye and dry on the cornea overnight.
Hamilton, who has 20-15 vision, unsuccessfully tried colored contact lenses to combat his dramatic dropoff in production during day games. It has been a mysterious problem that he now at least feels as though he understands.
The All-Star outfielder has been told that blue eyes allow more light into the cornea, making seeing the baseball more difficult in daylight. He expounded on that theory Thursday morning.
"I've got a good explanation for it. This is as clear as I can make it," Hamilton said. "We play at nighttime, sweat -- blue eyes, obviously, are harder anyway -- but playing at nighttime, you sweat a lot, you wipe your eyes, sweat gets on your cornea and dries overnight. Then, you come out midday the next day and instead of the light going straight through your cornea, it hits the dry sweat and disperses and makes everything brighter."
That's where the drops and eyelid scrubs come in following the previous night's games.
"I use them at nighttime to get the dry sweat off," Hamilton said. "I've played two games since I've been doing it and I've had a lot better at-bats. I've seen the ball a lot better."
Hamilton is batting .111 (7-for-63) in day games with no home runs and 24 strikeouts. At night, the reigning American League batting champ is hitting .365 (66-for-181) with 13 home runs and 21 strikeouts.
Rangers manager Ron Washington said on Wednesday that he has no intention of taking Hamilton out of Thursday's lineup as Texas seeks to win the series and push its AL West lead back to five games, or to drop Hamilton from his usual three-hole in the batting order.
Washington said it would be up to Hamilton to remove himself from the daytime lineup, something Hamilton does not plan to do.
The manager said even if Hamilton continues to struggle from the plate, his presence in the field and in the batter's box is an advantage.
"If you don't get no hits, run some [fly balls] down, throw somebody out, take a walk," Washington said. "I don't know what he's seeing, what he's not seeing, but I know one thing for sure: We certainly don't want him to use that as an excuse. Just give us what you got, that's all we want."
Hamilton recently started wearing sunglasses during batting practice. He wears sunglasses in the field, but he hasn't been comfortable wearing them at the plate because he said it alters his depth perception.
He equated it to playing golf, saying he always removes his sunglasses before stepping up to the ball.
Hamilton said he is feeling more confident after his last two day games since he started using the eye drops and eyelid scrubs. The Rangers played a day game in Arlington against Oakland prior to the All-Star break and then another last Sunday at Seattle. Hamilton was 1-for-7 in the two games with a walk and three strikeouts, but he came away encouraged because he said he saw the ball better and had more competitive at-bats.
"Hopefully, it works just as good as it did the last couple of times," Hamilton said before Thursday's loss. "I haven't had enough day games to really see if it works."
Jeff Caplan is a reporter and columnist for ESPNDallas.com.