Hamilton, who left the Sept. 17 game against Los Angeles because of an eye issue, was diagnosed with ocular keratitis. It caused Hamilton's corneas to dry out and made his eyes feel like they were stuck open and transfixed on one spot.
The good news is that since Hamilton was diagnosed, he's cut down on caffeine, chocolate, energy drinks and medication, all things that make the condition worse.
He was in the Texas starting lineup Monday in his familiar No. 3 spot and playing centerfield.
"It's the same thing I had last year," Hamilton said. "I got drops for it last year. Not knowing caffeine, chocolate, antihistamines, decongestant stuff and all that dries them out even worse."
Hamilton knows that now and is feeling better. He hit at Rangers Ballpark on Sunday and ran in the outfield. Hamilton left last Monday's game with what then was thought to be a sinus issue. He didn't travel with the team to Seattle and returned to Texas for the diagnosis.
Hamilton said he started having issues in the team's last home stand and it got worse. He left after two at-bats against the Angels. He said it was difficult to leave the team during the stretch run, but he had to figure out what was causing the problem.
"The vision was fine," Hamilton aid. "I would move my head and my eyes wouldn't move. It just feels better now. It wasn't impacting my vision. It was impacting my ability to be ready to play the game."
Hamilton said he was drinking coffee in the morning and afternoons and then having an energy drink before games. He followed that up with chocolates. It didn't help matters that when it was thought to be a sinus issue, he was taking medicine.
Texas manager Ron Washington said he had no problem putting Hamilton back in the lineup because the issue was solved.
While Hamilton was relieved by the diagnosis, he also wasn't surprised about it given his track record of odd issues. Hamilton had eye issues last year that affected him in day games. He eventually settled on eye drops. He struggled at the plate earlier this year because he had a hard time giving up chewing tobacco.
"Dude, it's me we're talking about here," Hamilton said. "Guys, it's me, Josh. It's going to be something weird. Just go with it."