Understanding the Types of Amblyopia

Posted on Nov 21, 2023

Amblyopia, commonly known as “lazy eye,” is a condition characterized by reduced vision in one eye that cannot be attributed to any underlying eye disease. This vision impairment occurs despite the use of corrective measures, such as glasses or contact lenses. Amblyopia can manifest in several forms, with each type presenting unique characteristics and causes. In this blog, we will delve into the four main types of amblyopia and provide an overview of their respective presentations.

 

  1. Refractive Amblyopia

Refractive amblyopia, also known as anisometropic amblyopia, occurs when there is a significant difference in the refractive error between the two eyes. Refractive error refers to the inability of the eye to focus properly, resulting in blurred vision. In this type of amblyopia, one eye has a significantly higher refractive error, such as nearsightedness (myopia), farsightedness (hyperopia), or astigmatism, compared to the other eye. The brain begins to rely more heavily on the eye with clearer vision, causing the weaker eye to deteriorate over time.

Treatment for refractive amblyopia typically involves correcting the significant difference in the refractive error by prescribing glasses or contact lenses. In some cases, patching or blurring the “better” eye may be necessary to encourage the weaker eye to develop better visual acuity.

  1. Strabismic Amblyopia

Strabismic amblyopia, also known as lazy eye due to misalignment, occurs when the eyes are misaligned or have a significant difference in their alignment. Strabismus refers to a condition where the eyes do not align properly, causing one eye to turn inward, outward, upward, or downward. The misalignment prevents the brain from effectively coordinating the visual input from both eyes, leading to poor vision in the misaligned eye.

In strabismic amblyopia, the brain begins suppressing or ignoring the visual input from the misaligned eye to prevent double vision. Over time, this lack of stimulation causes the visual acuity in the affected eye to deteriorate. Treatment typically involves correcting the misalignment through methods such as wearing special corrective glasses, using eye exercises, or in some cases, undergoing surgical intervention. Patching or blurring the “better” eye may also be necessary to encourage the weaker eye to develop better vision.

  1. Meridional Amblyopia

Meridional amblyopia, also known as astigmatic amblyopia, occurs as a result of significant astigmatism in one eye. Astigmatism is a refractive error caused by an irregularly shaped cornea or lens that leads to distorted or blurred vision. In meridional amblyopia, the astigmatism is present in one eye, while the other eye has normal vision.

The brain’s preference for clearer visual input causes it to suppress the eye affected by astigmatism. This leads to reduced visual acuity and amblyopia in the affected eye. Treatment for meridional amblyopia involves correcting the astigmatism by prescribing glasses or contact lenses. Patching or blurring the “better” eye may also be necessary to encourage the weaker eye to develop better vision.

  1. Deprivation Amblyopia

Deprivation amblyopia, also known as occlusion amblyopia, occurs when there is a structural or physical obstruction in one eye that prevents normal visual input. This obstruction can be caused by conditions such as cataracts, ptosis (droopy eyelid), or any other condition that physically blocks the light from entering the eye adequately.

Because the deprived eye does not receive proper visual stimulation during critical periods of development, it results in poor visual acuity and impaired vision. Treatment for deprivation amblyopia often involves addressing the underlying cause of the deprivation, such as surgical intervention to remove cataracts or correct eyelid abnormalities. Additionally, patching or blurring the “better” eye may be necessary to encourage the weaker eye to develop better vision.

 

Our eye doctors at Eye Theory in Houston, TX excel in the prescription of contact lenses, glasses and various eye diseases. Call our optometrist at 832.831.7386 or schedule an appointment online if you would like to learn more about amblyopia. Our eye doctor, Dr. Jonathan Tsao, provides the highest quality optometry services and eye exams in the Midtown, Downtown, Museum District, Montrose, East Downtown, and Southside Commons (Southside Place) vicinities of Houston, Texas as well as our newest location in the Stone Oaks neighborhood of San Antonio, Texas.

 

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