Effects of caffeinated coffee consumption on intraocular pressure, ocular perfusion pressure, and ocular pulse amplitude: a randomized controlled trial.
Jiwani A Z, Rhee D J, Brauner S C, Gardiner M F, Chen T C, Shen L Q et al.
This study found caffeinated coffee statistically, but not clinically, increased intraocular pressure and ocular perfusion pressure in glaucoma patients/suspects, suggesting minimal clinical impact from one cup.