Amblyopia (patient information): Difference between revisions
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==What are the causes of amblyopia?== | ==What are the causes of amblyopia?== | ||
[[ | Amblyopia is caused primarily by one of two factors: improper alignment (known as [[strabismus]]) and unequal [[refractive power]]. If the child's eyes are not properly aligned, the brain will receive two different images from the eyes. Perceiving [[double vision]], the brain will not use the image from the weaker eye. This eye, through lack of use, gradually loses its ability to function. The second primary cause of amblyopia is significantly unequal [[refractive power]] in the two eyes. For example, one eye may be very [[farsighted]] or [[nearsighted]] while the other eye may have normal [[vision]]. Again the [[brain]] receives different images from the two eyes and suppresses the image from the weaker eye. | ||
Other causes include: | Other causes of amblyopia include: | ||
* [[Heredity|Family history]] of amblyopia | |||
* [[Astigmatism]] in both eyes | * [[Astigmatism]] in both eyes | ||
* Childhood [[cataracts]] | * Childhood [[cataracts]] | ||
==Who is at risk for amblyopia?== | ==Who is at risk for amblyopia?== | ||
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What is amblyopia?
Amblyopia (commonly referred to as lazy eye) is the failure of one eye, although otherwise physically normal, to develop normal vision and see details.
The brain and the eye work together to produce vision. Light enters the eye and is changed into nerve signals that travel along the optic nerve to the brain. Amblyopia is the medical term used when the vision in one of the eyes is reduced because the eye and the brain are not working together properly. The eye itself looks normal, but it is not being used normally because the brain is favoring the other eye. As a result, the affected eye fails to develop normal vision and see details. It has been estimated to affect 1–5% of the population.[1]
What are the symptoms of amblyopia?
Amblyopia often gives no clues to the untrained observer. In fact, many people with amblyopia, especially those who are only mildly so, are not even aware they have the condition until tested at older ages, since the vision in their stronger eye is normal. However, people with more severe amblyopia may experience associated visual disorders, most notably poor depth perception. Other symptoms include:
- Eyes that turn in or out
- Eyes that do not appear to work together
- Poor spatial acuity
- Low sensitivity to contrast
- Problems of binocular vision:
- Limited stereoscopic depth perception
- Difficulty seeing the three-dimensional images in hidden stereoscopic displays such as autostereograms.[2]
- Some "higher-level" deficits to vision, such as reduced sensitivity to motion [3]
What are the causes of amblyopia?
Amblyopia is caused primarily by one of two factors: improper alignment (known as strabismus) and unequal refractive power. If the child's eyes are not properly aligned, the brain will receive two different images from the eyes. Perceiving double vision, the brain will not use the image from the weaker eye. This eye, through lack of use, gradually loses its ability to function. The second primary cause of amblyopia is significantly unequal refractive power in the two eyes. For example, one eye may be very farsighted or nearsighted while the other eye may have normal vision. Again the brain receives different images from the two eyes and suppresses the image from the weaker eye.
Other causes of amblyopia include:
- Family history of amblyopia
- Astigmatism in both eyes
- Childhood cataracts
Who is at risk for amblyopia?
How to know you have amblyopia?
When to seek urgent medical care
Treatment options
Diseases with similar symptoms
Where to find medical care for amblyopia
Directions to Hospitals Treating amblyopia
Prevention of amblyopia
What to expect (Outlook/Prognosis)
Sources
http://www.nei.nih.gov/health/amblyopia/amblyopia_guide.asp
http://www.nlm.nih.gov/medlineplus/ency/article/001014.htm
http://www.sightandhearing.org/sightcenter/ambly.asp
- ↑ Weber, JL; Wood, Joanne (2005). "Amblyopia: Prevalence, Natural History, Functional Effects and Treatment" ([dead link] – Scholar search). Clinical and Experimental Optometry. 88 (6): 365–375. doi:10.1111/j.1444-0938.2005.tb05102.x. PMID 16329744.
- ↑ Tyler, C.W. (2004). "Binocular Vision In, Duane's Foundations of Clinical Ophthalmology. Vol. 2, Tasman W., Jaeger E.A. (Eds.), J.B. Lippincott Co.: Philadelphia".
- ↑ Hess, R.F., Mansouri, B., Dakin, S.C., & Allen, H.A. (2006). "Integration of local motion is normal in amblyopia". J Opt Soc Am a Opt Image Sci Vis. 23 (5): 986–992. doi:10.1364/JOSAA.23.000986. PMID 16642175.