How to use the Red Free Function.

The Red Free function will apply a Red Free filter to the entire image in the viewing area. This will result in a more defined and reflection free version of the vessels, which is especially important when analysing bulbar and lid redness.

Red Free Tool

Step 1: Select an image from the image's column on the left side, Figure 1. 

Figure 1

Step 2: To activate this function simply click 'Red Free', Figure 2. 

Figure 2

Step 3: To deactivate the filter simply click the 'Red Free' again. 


  • Please take into account that the core functions (Bulbar, Lid, Staining) cannot be applied over the Red Free filter, as well as the other filters (Wratten, Enhance). 

  • Additional tools like Annotate, Draw, and Ruler can be used while the Red Free filter is applied.