Vision Science Research Group

How is Visual acuity measured?

    How is Visual Acuity Measured?

    Visual acuity is often measured by the Optometrist, Optician or Orthoptist by asking the patient to read progressively smaller letters presented on a wall chart six meters (20 feet) away.

    Children may be asked to identify letters or pictures either by naming or matching them with a key card.


    Letter and picture tests measure recognition (or identification) acuity.

    For more information on recognition acuity click here

    Young children or those with communication difficulties can be tested using methods that don’t require the patient to speak or point. Most commonly looking responses are assessed to estimate visual acuity. These tests measure resolution acuity.

    For more information on resolution acuity click here