by Julieanne Kost
Almost all of the editing panels in Lightroom’s Develop module display a small “light switch” icon on the left side of the panel’s header. Click the “light switch” to toggle the visibility of changes made in that panel.
The Graduated Filter and Adjustment Brush also have the “lights switch” icon to toggle the visibility of the changes made with the respective tool. Note however that the icon is displayed at the bottom left of the tool’s options (as there is no Panel header for these tools).
Tapping the “\” (Backslash) key toggles changes made in all of the panels.