Group 2 - Healthy control participants:  Inclusion criteria will include:  Absence of ocular disease in either eye Male or female, aged 18 years or older The absence of significant media opacities Ability to understand nature/purpose of the study and to provide informed consent Ability to follow instructions and complete the study Ability to speak English  Exclusion criteria will include:  Any systemic disease likely to affect visual performance Presence of any ocular disease Hearing impairment sufficient to interfere with hearing instructions Poor understanding of English language and/or alphabet Any condition which, in the investigator's opinion, would conflict or otherwise prevent the subject from complying with the required procedures, schedule, or other study conduct.