The electroretinogram (ERG) is a diagnostic test that measures the electrical activity generated by cells in the retina in response to a light stimulus. Typically, an ERG is recorded with white flash when the pupil is dilated. RETeval Visual Diagnostic Device (RETeval) generates an array of color flashes, which allows studying whether color flash would be a useful diagnostic tool.

Full pupil dilation is required to obtain a response from the whole retina. However, this requirement often limits a patient's flow in the clinic and increases the overall time patients spend at the eye practitioner. RETeval provides the possibility of recording ERGs in un-dilated pupils therefore making the whole exam easier and shorter. These results need to be compared to the classic, fully dilated ERG and evaluated for efficiency.

The purpose of this research study is to use the RETeval device to measure the eye's electrical response and how it changes with different stimuli such as changing flash color or pupil dilation.

Inclusion Criteria:

• healthy adult volunteers
• volunteers able to get their pupil fully dilated

Exclusion Criteria:

• pregnant women
• children
• subjects with
• light sensitivity
• photosensitive epilepsy
• allergies or sensitivity to pupil dilation ophthalmic solutions
• history of glaucoma
• cardiac dysrhythmia will not be invited to participate in this study.
• Pregnancy status, light sensitivity and photosensitive epilepsy will be based on volunteer's providing this information at the time of signing the consent form