terminology

Last reviewed 01/2018

The terms used for description in the realm of squints include:

• binocular single vision - the ability to use both eyes to create a common perception
• orthophoria - perfect ocular balance in the binocular state
• porphoria - the eyes move out of the aligned state when they are dissociated - latent squint
• exophoria - the eyes diverge
• esophoria - the eyes converge
• hyperphoria - the visual axis of one eye moves vertically with respect to the other one
• manifest squint - if, in the binocular state, the eyes have different visual directions
• non-paralytic squint - the angle of the squint remains unaltered regardless of the direction of gaze
• paralytic squint - if the angle of non-alignment varies with a change in direction of gaze, the squint is incompetent and the causes is usually an infranuclear muscle palsy. This situation can also occur in a mechanical restriction of eye movement