Visual Function Lab


Night Vision

Night vision goggles operate by capturing infrared frequency light and displaying it as visible light onto a small screen placed in front of the eye. One of the drawbacks of this technology is the difficulty for the user in perceiving the depth of objects displayed on the night vision screen. There are differing opinions for why this occurs, and in our lab we are researching the possibility that difficulty in depth perception is due to the way that goggles limit eye movement.

In order to properly use night vision goggles, the user must focus their eye on a stationary point - the screen inside of the eyepiece. As a result, in order to gauge depth, the user must usually move their head. In one experiment, a participant sits wearing a pair of night vision goggles and attempts to move a pin to an equal depth as a pin placed earlier as part of the experiment. Using an eyetracker, how much (or how little) the eyes move as they look at objects from inside the goggles can be recorded to see how significant an effect staring at a single point has on the ability to perceive depth.

Further understanding how the eyes perceive depth in this way can potentially lead to more effective ways of presenting it on two-dimensional displays.

Alcohol and Eye Movement

Another way that the ability to perceive depth through motion is affected is by alcohol. While it is well understood that alcohol affects the ability to judge distances correctly, based on our findings, it may be more affected than we thought.

Effects on amblyopia and esotropia

Further understanding how these mechanisms work will allow us to understand what is happening inside the brain when an individual suffers from conditions like amblyopia or esotropia, which forces eyes to view the world through two distinct focal points instead of a single, unified point. Understanding how the brain interprets depth from each eye independently may help us better understand how the conditions are caused, and could potentially be better corrected.