Illinois Vision Certification Practice Test

What is a key characteristic of phoria?

1. It is a permanent condition

2. It can be readily observed

3. It is an observable tendency to deviate

4. It indicates loss of visual acuity

The correct answer is: It is an observable tendency to deviate

Phoria is characterized as an observable tendency to deviate from alignment of the eyes under certain conditions, specifically when the eyes are not focused on a target. Unlike a tropia, which is a constant deviation that is always present, phoria refers to a situation where the eyes would misalign when they are not actively being used to fixate on an object. This means that while the eyes may appear to be properly aligned when focusing, there is a latent tendency for them to deviate, which can be brought to light when one eye is covered or when the binocular fusion effort is relaxed. Understanding this characteristic is crucial for practitioners as it helps them identify issues related to binocular vision and the need for possible interventions. The assessment of phoria often informs treatment strategies for conditions such as strabismus or accommodative dysfunctions. Thus, recognizing phoria's tendency to deviate rather than being a constant deviation enables clinicians to differentiate between various visual conditions more effectively.