Users can somewhat accurately target small objects just by moving their gaze. However, it is considerably easier for users to do fine targeting tasks if given a visual reticle (visual aid to track targets) to help them aim. Display a reticle when the user is doing fine targeting.
If you are concerned that displaying a reticle may reduce immersion or create unnecessary visual clutter, follow these guidelines:
Display the reticle only when the user approaches a target that they can activate.
Project a light source, or design obvious hover states, for objects that the user can target.