Inclusion Criteria:  Be 18 years of age or older at the time of informed consent Irrespective of sex Irrespective of race or ethnicity Be willing and able to provide written informed consent by subject or legally designated representative prior to any study procedures  Exclusion Criteria:  Have only one functional eye Have one eye with poor or eccentric fixation Have corneal scarring or have had corneal surgery, including corneal laser surgery in either eye Have microphthalmos in either eye Have buphthalmos in either eye Be a contact lens wearer (persons wearing soft contact lenses within the past 3 months and/or hard contact lenses within the past 6 months) Have dry eyes (persons who have been diagnosed by a physician and are currently using prescription drugs or routinely using artificial tears) Uncontrollably blink, squint, wink, twitch or squeeze eye(s) - blepharospasm Have nystagmus in either eye Have keratoconus in either eye Have any other corneal or conjunctival pathology or infection in either eye Have central corneal thickness is less than 500μm or more than 600μm Be allergic to eye drop anesthetics Be allergic to sodium fluorescein