Eyecharts (Litterate / Tumbling "E")

ILLITERATE (Tumbling "E" )

Tumbling "E" charts, also referred to as Illiterate "E" tests, are useful for testing patients that are illiterate or mute. Patients simply have to sign or gesture which direction they see the "E" facing. Tumbling "E" charts are considered highly reliable.

SNELLEN (Literate)

The optotypes have the appearance of block letters, and are intended to be seen and read as letters. They are not, however, letters from any ordinary typographer's font. They have a particular, simple geometry in which:

• the thickness of the lines equals the thickness of the white spaces between lines and the thickness of the gap in the letter "C"
• the height and width of the optotype (letter) is five times the thickness of the line.

All charts are based on visual angle of one minute.