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We are temporarily suspending all NEW uses of the DVA due to technological issues. We are exploring solutions to the problem but are not able to support new installations of DVA. 


July 2014


NIH Toolbox Dynamic Visual Acuity Test


This test is a measure of gaze stability, which helps identify individuals who may have a deficit of the vestibular system (which regulates internal balance). The NIH Toolbox Visual Acuity Test must be administered followed by the DVA Test. 

 Participants are seated 12.5 feet from a computer monitor at eye level. For the DVA Test, participants wear lightweight headgear that contains a rate sensor, and are asked to move the head back and forth, as if saying “no.” Once the head is measured to be moving at greater than 180 degrees per second, an optotype flashes on the monitor, and the participant is asked to identify it. Smaller optotypes are displayed as the participant correctly identifies letters, and larger ones are displayed if the participant cannot correctly identify the letter shown, until the computer has calculated the smallest size that the participant can see with the head moving. This is calculated separately for head rotation leftward and rightward from center (though the participant continues shaking the head both ways), and this performance is compared to the participant’s visual acuity when the head was stationary (the NIH Toolbox Visual Acuity Test score, sometimes referred to as “static” visual acuity in the context of the DVA test).

The difference between “static” and dynamic visual acuity represents the vestibular contribution to gaze stability.

The DVA Test takes approximately six minutes to administer and is recommended for ages 3-85.


Low Vision
Decreased Hand Function
Mobility Impairment
Hard of Hearing
Speech impairment
Reading Impairment
N= not accessible and not feasible to make accessible
P=Not accessible, but can be made accessible with reasonable accommodations
A= Currently accessible
NA=Not applicable – test not administered to people with visual acuity of less than 20/400 as measured by the Static Visual Acuity Measure