The purpose of this study is to evaluate if critical flicker fusion is a more reliable method for detection of early glaucoma compared to automated visual fields in comparison to subjects without evidence of glaucoma or optic nerve disease.

Our hypothesis is that critical flicker fusion (CFF) is a more reliable method for detection of early glaucoma compared to automated visual fields in comparison to subjects without evidence of glaucoma or optic nerve disease. We aim to evaluate the structure of the optic nerve and compare it to results of visual fields and CFF. The CFF will also be correlated with intraocular pressure (IOP) measurements to observe if it may be more closely related than visual fields. This may become an additional tool to detect glaucoma in those with unreliable visual fields or who are unable to perform a visual field from physical or mental limitations.

Inclusion:

• Glaucoma Suspects:
• Abnormal optic disc appearance with increased cup to disc ratio, or
• Increased intraocular pressure >21 in either eye
• Control Subjects:
• Normal appearing optic discs
• Normal intraocular pressure (<21)

Exclusion:

• Other ocular pathology
• History of seizures or epilepsy

Subjects will be selected from routine clinic patients seen at the Eye Center at Nassau University Medical Center, in East Meadow, NY.