Table of ContentsView AllTable of ContentsWhat Is a Tropia?What Is a Phoria?ExamplesCausesDiagnosis
Table of ContentsView All
View All
Table of Contents
What Is a Tropia?
What Is a Phoria?
Examples
Causes
Diagnosis
This article covers examples of phoria and tropia misalignments as well as testing for the conditions.
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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.
Examples of Phoria and Tropia Misalignments
If these terms seem confusing, consider two types of people who may come to an eye care specialist complaining of double vision. 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.
Eye doctors also categorize them as right eye or left eye or alternating between the eyes. They can also be labeled intermittent or constant.
2:12Everything You Need to Know About Tropias and Phorias
2:12
Everything You Need to Know About Tropias and Phorias
What Causes Phorias and Tropias?
To compensate, a child will attempt to focus their eyes intently, which induces an accommodation reflex. With this reflex, the eyes will increase the refractive power of the human lens as well as decrease the pupil size. Depending on the size of the object and the amount of blur, the eyes turn inwards—a process known as convergence.
Thus, when a child’s eyesight is extremely farsighted, the process that is originally designed to bring clearer near vision occurs in the distance. This causes the eye that has the farsighted refractive error to turn inward, even when looking at objects in the distance. This is calledesotropia, specifically, accommodative esotropia (there are other types of esotropia as well).
Hyperopia (Farsightedness): What Can You See?
How Do You Test for Phorias and Tropias?
Your eye doctor may want to measure the alignment of your eyes. During the cover test portion of aneye examination, your eye doctor will alternately cover and uncover your eyes while you fixate on a target. If your eye moves upon being uncovered, you have a phoria.
We all have a normal phoric resting position. Some people have a larger than normal phoria that they may be able to compensate for most of the time. However, because the phoria is much larger than what is considered normal, they cannot always compensate for it when fatigued. 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.
Can a Phoria Lead to a Tropia?
It’s possible for a pre-existing phoria to eventually progress to a tropia.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Ebeigbe JA, Emedike CM.Parents' awareness and perception of children’s eye diseases in Nigeria.J Optom. 2017;10(2):104–110. doi:10.1016/j.optom.2016.06.001Ogun O.Red flags in neuro-ophthalmology.Community Eye Health. 2016;29(96):64–65American Optometric Association.Strabismus (crossed eyes).Jones-Jordan L, Wang X, Scherer RW, Mutti DO.Spectacle correction versus no spectacles for prevention of strabismus in hyperopic children.Cochrane Database Syst Rev. 2014;8(8):CD007738. doi:10.1002/14651858.CD007738.pub2American Academy of Ophthalmology. EyeWiki.Cover tests.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Ebeigbe JA, Emedike CM.Parents' awareness and perception of children’s eye diseases in Nigeria.J Optom. 2017;10(2):104–110. doi:10.1016/j.optom.2016.06.001Ogun O.Red flags in neuro-ophthalmology.Community Eye Health. 2016;29(96):64–65American Optometric Association.Strabismus (crossed eyes).Jones-Jordan L, Wang X, Scherer RW, Mutti DO.Spectacle correction versus no spectacles for prevention of strabismus in hyperopic children.Cochrane Database Syst Rev. 2014;8(8):CD007738. doi:10.1002/14651858.CD007738.pub2American Academy of Ophthalmology. EyeWiki.Cover tests.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Ebeigbe JA, Emedike CM.Parents' awareness and perception of children’s eye diseases in Nigeria.J Optom. 2017;10(2):104–110. doi:10.1016/j.optom.2016.06.001Ogun O.Red flags in neuro-ophthalmology.Community Eye Health. 2016;29(96):64–65American Optometric Association.Strabismus (crossed eyes).Jones-Jordan L, Wang X, Scherer RW, Mutti DO.Spectacle correction versus no spectacles for prevention of strabismus in hyperopic children.Cochrane Database Syst Rev. 2014;8(8):CD007738. doi:10.1002/14651858.CD007738.pub2American Academy of Ophthalmology. EyeWiki.Cover tests.
Ebeigbe JA, Emedike CM.Parents' awareness and perception of children’s eye diseases in Nigeria.J Optom. 2017;10(2):104–110. doi:10.1016/j.optom.2016.06.001
Ogun O.Red flags in neuro-ophthalmology.Community Eye Health. 2016;29(96):64–65
American Optometric Association.Strabismus (crossed eyes).
Jones-Jordan L, Wang X, Scherer RW, Mutti DO.Spectacle correction versus no spectacles for prevention of strabismus in hyperopic children.Cochrane Database Syst Rev. 2014;8(8):CD007738. doi:10.1002/14651858.CD007738.pub2
American Academy of Ophthalmology. EyeWiki.Cover tests.
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