This multi-center, prospective, observational (non-interventional) study is the third in a series to measure structural parameters of the optic nerve head, the peripapillary retinal nerve fiber layer, and the macula using the Heidelberg Spectralis OCT device. This study is conducted in normal volunteers of various non-Caucasian ethnic group, and data will be combined with Caucasian subjects to be representative of the US population: (1) Hispanic Descent, (2) Black or African American Descent, (3) Asian Descent, (4) American Indian or Alaskan Native Descent. This study will complement the previous study S-2012-1 NORM-cc, in which normal data from Caucasian individuals were collected.