20/20 – Patients see at 20 ft. what a person with normal vision sees at 20 ft.
20/25 – Patients see at 20 ft. what a person with normal vision sees at 25 ft.
20/30 – Patients see at 20 ft. what a person with normal vision sees at 30 ft.
20/40 – Patients see at 20 ft. what a person with normal vision sees at 40 ft.
J1+ – Patients can read 3pt font size (for example, stock quotes in the newspaper)
J1 – Patients can read 4pt font size (for example, stock quotes in the newspaper)
J2 – Patients can read 5pt font size (for example, the normal type on a classified ad)
J6 – Patients can read 6pt font size (for example, the normal newspaper size)