This article covers examples of phoria and tropia misalignments as well as testing for the conditions.
Understanding Tropias
A tropia is a misalignment of the eyes that is always present.
Even when the eyes are both open and trying to work together, large angle misalignments are apparent.
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A tropia is easily seen by a healthcare provider conducting a cover/uncover eye test.
What Is a Phoria?
A phoria can be diagnosed by conducting the cover/cover test.
One person complains of double vision and one eye is completely turned in and crossed toward the nose.
The eye never straightens up and is always turned in.
It is quite obvious because it gives a crossed-eye appearance.
This person has a tropia.
Sometimes, they may even see double when watching TV.
This person probably has a phoria.
They can also be labeled intermittent or constant.
What Causes Phorias and Tropias?
Phorias or tropias can be sparked by a variety of factors.
To compensate, a child will attempt to focus their eyes intently, which induces an accommodation reflex.
This is calledesotropia, specifically, accommodative esotropia (there are other types of esotropia as well).
How Do You Test for Phorias and Tropias?
Your eye doctor may want to measure the alignment of your eyes.
If your eye moves upon being uncovered, you have a phoria.
We all have a normal phoric resting position.
As a result, their phoria may manifest itself and become a tropia.
Can a Phoria Lead to a Tropia?
It’s possible for a pre-existing phoria to eventually progress to a tropia.
If a large amount of phoria exists, your eyes are not aimed at the target while at rest.
Keeping both eyes fixated on the target requires an effort by you, possibly causing eyestrain or headaches.
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