Final answer:
A nurse should advise a glaucoma patient to limit or avoid excessive caffeine consumption to prevent a possible increase in intraocular pressure.
Step-by-step explanation:
When educating a client diagnosed with glaucoma on self-care principles, a nurse would encourage the client to limit or refrain from consuming excessive amounts of caffeine. Caffeine can potentially elevate intraocular pressure, which is detrimental to individuals with glaucoma. Moderate aerobic exercise can be beneficial, and performing regular eye exercises and reading for extended periods do not typically need to be restricted unless otherwise advised by a healthcare provider.