On-screen tools
Training tools
Clinic equipment, running in your browser. These are what make most of the exercise library workable with no props at all — adjustable, paced, scored, and randomised so nothing can be memorised. Nothing to install.
What a screen can and cannot do
A flat display at a fixed distance cannot change your focusing or eye-teaming demand on its own. The honest ways round that are free fusion (crossing or relaxing your eyes on two side-by-side targets), red/green glasses, or genuinely using two devices at different distances — and that is exactly what these tools do. Where a tool is an approximation rather than the real stimulus, it says so on its own page.