Upon investigating the differences in intraocular pressure (IOP) and ocular perfusion pressure (OPP) between low- and high-caffeine consumers, a team of Spanish researchers found that IOP responsiveness to caffeine ingestion is subject to tolerance effects and could be due to alterations in the adenosine receptor system caused by chronic caffeine consumption; the findings could have important implications for glaucoma management, they suggest. Find out more about the link between caffeine and IOP in this feature from Review of Optometry. Read More.