Illumination and Position

A child's needs in terms of luminance level and posture are considered during testing. Testing is usually started in an optimal posture. Later observations are made in all the postures where the child is positioned during the day.

Infants who seem to be blind should be observed also at low luminance levels. Many infants with with severe photophobia are so dazzled in room light that they do not see anything. They have not yet learned to open their eyes for only brief moments (“light catcher”) to prevent overexposure. In dim light they may open their eyes and reach for objects. With good protective goggles and filters their vision can be much like our vision in dusk.