Optonet Vision Unit Documentation

Please note that this User Guide is being currently updated; new sections will be added shortly.

  1. QuickStart Guide (in 5 steps)
    1. Step 1. Choosing Hardware
    2. Step 2. Installation and Calibration
    3. Step 3. Menus
    4. Step 4. Control of Menus and Charts
    5. Step 5. Customise Sequences of Charts
    6. How to check if my charts are well calibrated?
  2. Home-based Vision Training (Orthoptics)
    1. Patient Selection
    2. Calendar
    3. Daily Exercise Program
    4. Parameters
    5. Comments
    6. Login Credentials for the patient
    7. Attaching documents
    8. Save Therapy
    9. Access as Patient
    10. Remote monitoring of patient progress
    11. Management of Patient’s Access
  3. Virtual Eye Clinic
  4. Visual Acuity
    1. logMAR VA
    2. Logarithmic Notation
    3. VA Rating (VAR) or VA Score (VAS)
    4. VA Tools Menu
      1. Selecting Rows and VA Values.
      2. Visual Acuity Range
      3. Bi-Chrome Function
      4. Isolated Optotypes (Rows, Columns and Letters)
      5. Contrast
      6. Randomizing the order of optotypes
      7. Vanishing Optotypes
      8. Intermediate Steps
      9. Tablet as a remote controller for VA
    5. VA Optotypes
      1. Sloan letters
      2. British Letters
      3. Numbers
      4. Landolt Optotype "C"
      5. E of Snellen
    6. References Visual Acuity
    7. Paediatric Visual Acuity
      1. Test of “Broken Glasses”
      2. Symmetrical Optotype
      3. References Paediatric Visual Acuity
    8. Automated Visual Acuity Testing
      1. ETDRS, Bailey-Lovie, Snellen E, Numbers and Landolt C
      2. Symmetrical Letter Chart
      3. Broken Glasses Chart
      4. References Automated VA Testing
      5. VA Testing Protocol > 8 years old (printable document)
      6. VA Testing Protocol ≤ 8 years old (printable document)
  5. Setup
    1. Colour Calibration

4.5.5.E of Snellen #

This optotype uses the Snellen “E” drawn on a 5×5 matrix. The E can be oriented in one of the 4 positions (left, right, up and down).

 

 

Snellen “Es” have traditionally been used in children, although many children cannot correctly identify these four orientations. In addition, Snellen’s “E’s” are similar to grating acuity, which appear to be less sensitive for identifying amblyopia than recognition acuity.

« Landolt Optotype "C"References Visual Acuity »
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