Eye Dominance Test (Miles Test)

What it measures

Your ocular (eye) dominance — which of your two eyes your brain prefers for precise aiming and alignment. This is the 'sighting' eye you naturally use to line things up, and it is separate from which eye sees more clearly.

How it works

This uses the Miles test, a standard sighting method. You extend both arms, overlap your hands to make a small triangular opening, and centre a distant object in the gap with both eyes open. When you then close each eye in turn, the object stays put through the opening for your dominant eye and appears to jump aside for the non-dominant one. We repeat the check over three trials and tally which eye wins to gauge how strong and consistent your dominance is.

Tips for an accurate result

• 1Use the furthest target you can — Distance sharpens the effect — a target across the street is clearer than one across a desk.
• 2Keep your hands and head still — Moving while you switch eyes muddies the result. Lock your arms and only change which eye is open.
• 3Repeat a few times — Dominance can feel weak. Doing several trials, as this test does, gives a more reliable picture than a single try.
• 4Try a smaller opening if unsure — If both eyes feel equal, shrink the triangular gap — a tighter window makes the dominant eye stand out more.