Optonet Vision Unit Documentation
Please note that this User Guide is being currently updated; new sections will be added shortly.
Two versions of the numbers chart are provided. The default version uses only the following four numbers: 8, 9, 6, 5, which are equally discriminable. The numbers are Arial type, drawn on a 5×4 matrix. The program has an option to use an expanded set of numbers (2, 3, 5, 6 and 9), drawn on a 5×5 matrix, similar to the Snellen “E”.
Number optotypes can be used in patients with communication difficulties when using letters (for example in people who speak another language). They could also be used on young children, although letter charts are recommended as soon as possible. The “broken glasses” test is another option which we will describe later.