You're right, the green dot with a tracking cursor is unlikely to be directly related to your camera being active on a modern Mac laptop. Here are some more probable explanations for the green dot you saw:
- AssistiveTouch: This is an accessibility feature on macOS that provides an on-screen cursor controlled by tapping or dragging on your trackpad or mouse. The green dot represents the location of this on-screen cursor. It's possible you might have accidentally activated AssistiveTouch with a keyboard shortcut (like Option-Shift-Control-F5) or by triple-clicking your trackpad (depending on your settings).
- Universal Control: If you have other Apple devices (like an iPad or another Mac) nearby and have Universal Control enabled, the green dot might represent the cursor position on that other device that your Mac cursor interacts with.
- Third-Party App Overlay: In rare cases, a third-party application might introduce an overlay that displays a green dot as part of its functionality.
Here's how to investigate further:
- Check AssistiveTouch: Go to System Preferences > Accessibility > AssistiveTouch. Ensure "AssistiveTouch" is unchecked. If it's checked, you might have accidentally activated it.
- Review Universal Control Settings: Go to System Preferences > General > AirPlay & Handoff. If you're using Universal Control, review the settings to see if anything might be causing the green dot to appear.
- Look for Conflicting Apps: If the issue persists, consider if any new apps were installed around the time you saw the green dot. Try temporarily quitting those applications to see if it makes a difference.
Since a reboot resolved the issue, it was likely a temporary glitch. However, by understanding the possible causes, you can troubleshoot if it appears again.
