What Causes Lazy Eye?Amblyopia, also called lazy eye, is a disorder of sight in which the brain fails to process inputs from one eye, and over time favours the other eye. It results in decreased vision in an eye that otherwise typically appears normal.It is the most common cause of decreased vision in a single eye among children and younger adults. The cause of amblyopia can be any condition that interferes with focusing during early childhood.
This can occur from poor alignment of the eyes, an eye being irregularly shaped such that focusing is difficult, one eye being more nearsighted or farsighted than the other, or clouding of the lens of an eye. After the underlying cause is fixed, vision is not restored right away, as the mechanism also involves the brain. Amblyopia can be difficult to detect, so vision testing is recommended for all children around the ages of four to five. Early detection improves treatment success.
Glasses may be all the treatment needed for some children. If this is not sufficient, treatments which force the child to use the weaker eye are used. This is done by either using a patch or putting atropine in the stronger eye. Without treatment, amblyopia typically persists. Treatment in adulthood may not be effective. Amblyopia begins at the age of five. In adults, the disorder is estimated to affect 1–5% of the population.
While treatment improves vision, it does not typically restore it to normal in the affected eye.[ Amblyopia was first described in the 1600s. The condition may make people ineligible to be pilots or police officers. The word amblyopia is from Greek ἀμβλύς amblys meaning "blunt" and ὤψ ōps meaning "sight
What Causes Blurred Vision? 1-computer vision syndrome symptoms of CVS include headaches, blurred vision, neck pain, fatigue, eye strain, dry eyes, irritated eyes, double vision, vertigo/dizziness, polyopia, and
2-Visual acuity (redirect from Twenty-twenty vision) brain. A common cause of low visual acuity is a refractive error (ametropia), or errors in how the light is refracted in the eyeball. Causes of refractive
3-A style Droopiness of the eyelid Scratchy sensation on the eyeball (itching) Blurred vision Mucous discharge in the eye Irritation of the eye Light sensitivity
4- Macular degeneration degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms
5- Glaucoma the presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred
6- Uveitis associated with other ocular problems. Burning of the eye Redness of the eye Blurred vision Photophobia Irregular pupil Blacked out sclera Headaches Signs of anterior
7- Fuchs' dystrophy of vision or glare or haloes particularly when driving at night. Individuals with symptomatic Fuchs dystrophy typically awaken with the blurred vision which
8- Orthostatic intolerance faints, they are well." Symptoms: Altered vision (blurred vision, "white-outs"/grey outs, blackouts, double vision) Anxiety Exercise intolerance Fatigue
9- Orthostatic hypotension tiredness may also occur. Some also report difficulty concentrating, blurred vision, tremulousness, vertigo, anxiety, palpitations (awareness of the heartbeat)10- Interstitial keratitis a patch of Hutchinson). Such vascularization is likely to result in blurring of vision secondary to corneal stromal scarring, the presence of ghost vessels
11 VergenceCHILDREN: What is Convergence Insufficiency Disorder? Eyestrain with reading or close work, blurred vision, blurry eyesight, exophoria, double vision, problems
12 Bates method (redirect from Natural vision improvement) farsightedness, astigmatism, and presbyopia (the age-related blurring of near-point vision) as consequences of the eye's shape and another basic anatomy
13- Amblyopia results in decreased vision in an eye that otherwise typically appears normal. It is the most common cause of decreased vision in a single eye among
14- Display motion blur now contribute to motion blur. The following factors are generally the primary or secondary causes of perceived motion blur in the video. In many cases, multiple
15- Blepharitis non-healing areas that may lead to bleeding. Blepharitis can also cause blurred vision due to a poor tear film. Tears may be frothy or bubbly, which can
16- Amaurosis fugax or blurring. Total or sectorial vision loss typically lasts only a few seconds but may last minutes or even hours. Duration depends on the cause of the
17- Maxwell Lord future where Magog's team attacks Parasite. In this vision, Parasite's absorption of Captain Atom causes an explosion that destroys everything within a large
18- Subdural hematoma in the ears (tinnitus) Blurred vision Deviated gaze or abnormal movement of the eyes. Subdural hematomas are most often caused by head injury, in which
19- Cytomegalovirus retinitis detachment), presenting as Blurred vision Blind spots Specks in your vision Cytomegalovirus (a type of herpes virus) is what causes cytomegalovirus retinitis
What Causes Diplopia Diplopiais diagnosed mainly by information from the patient. Doctors may use blood tests, physical examinations, computed tomography (CT), or magnetic resonance imaging (MRI) to find the underlying cause.
Classification One of the first steps in diagnosing diplopia is often to see whether one of two major classifications may be eliminated both may be present. That involves blocking one eye to see which symptoms are evident in each eye alone.
1-Binocular Binocular diplopia is double vision arising as a result of strabismus (in layman's terms "cross-eyed"), the misalignment of the two eyes relative to each other, either esotropia (inward) or exotropia (outward). In such a case while the fovea of one eye is directed at the object of regard, the fovea of the other is directed elsewhere, and the image of the object of regard falls on an extrafoveal area of the retina.
2 The brain calculates the visual direction of an object-based upon the position of its image relative to the fovea. Images falling on the fovea are seen as being directly ahead, while those falling on retina outside the fovea may be seen as above, below, right, or left of straight ahead depending upon the area of retina stimulated. Thus, when the eyes are misaligned, the brain perceives two images of one target object, as the target object simultaneously stimulates different, noncorresponding, retinal areas in either eye, thus producing double vision.
3 This correlation of particular areas of the retina in one eye with the same areas in the other is known as retinal correspondence. This relationship also gives rise to an associated phenomenon of binocular diplopia, although one that is rarely noted by those experiencing diplopia. Because the fovea of one eye corresponds to the fovea of the other, images falling on the two foveae are projected to the same point in space. Thus, when the eyes are misaligned, two different objects will be perceived as superimposed in the same space. This phenomenon is known as visual confusion'.
4 The brain naturally guards against the double vision. In an attempt to avoid double vision, the brain can sometimes ignore the image from one eye, a process known as suppression. The ability to suppress is to be found particularly in childhood when the brain is still developing. Thus, those with childhood strabismus almost never complain of diplopia, while adults who develop strabismus almost always do. While this ability to suppress might seem an entirely positive adaptation to strabismus, in the developing child, this can prevent the proper development of vision in the affected eye, resulting in amblyopia. Some adults are also able to suppress their diplopia, but their suppression is rarely as deep or as effective and takes much longer to establish, thus they are not at risk of permanently compromising their vision. In some cases, diplopia disappears without medical intervention, but in other cases, the cause of the double vision may still be present. Certain persons with diplopia who cannot achieve fusion and yet do not suppress may display a certain type of spasm-like irregular movement of the eyes in the vicinity of the fixation point
5 Monocular Diplopia can also occur when viewing with only one eye this is called monocular diplopia, or where the patient perceives more than two images, monocular polyopia. While serious causes rarely may be behind monocular diplopia symptoms, this is much less often the case than with binocular diplopia. The differential diagnosis of multiple image perception includes the consideration of such conditions as corneal surface keratoconus, subluxation of the lens, a structural defect within the eye, a lesion in the anterior visual cortex, or nonorganic conditions, but diffraction-based (rather than geometrical) optical models have shown that common optical conditions, especially astigmatism, can also produce this symptom.
6 Temporary Temporary binocular diplopia can be caused by alcohol intoxication or head injuries, such as concussion (if the temporary double vision does not resolve quickly, one should see an optometrist or ophthalmologist immediately). It can also be a side effect of benzodiazepines or opioids, particularly if used in larger doses for recreation, the antiepileptic drugs phenytoin and zonisamide, and the anticonvulsant drug lamotrigine, as well as the hypnotic drug zolpidem and the dissociative drugs ketamine and dextromethorphan. Temporary diplopia can also be caused by tired and/or strained eye muscles. If diplopia appears with other symptoms such as fatigue and acute or chronic pain, the patient should see an ophthalmologist immediately.
7 Voluntary Some people are able to consciously uncouple their eyes, either by over focusing closely (i.e. going cross-eyed) or unfocusing. Also, while looking at one object behind another object, the foremost object's image is doubled (for example, placing one's finger in front of one's face while reading text
What Is a Cataract
A cataract is a clouding of the lens in the eye which leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or double vision, halos around light, trouble with bright lights, and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts cause half of all cases of blindness and 33% of visual impairment worldwide
Cataracts are most commonly due to ageing but may also occur due to trauma or radiation exposure, be present from birth, or occur following eye surgery for other problems.
Risk factors include diabetes, smoking tobacco, prolonged exposure to sunlight, and alcohol.
The underlying mechanism involves the accumulation of clumps of protein or yellow-brown pigment in the lens that reduces transmission of light to the retina at the back of the eye.
Diagnosis is by an eye examination.
Prevention includes wearing sunglasses and avoiding smoking.
Early on the symptoms may be improved with glasses. If this does not help, surgery to remove the cloudy lens and replace it with an artificial lens is the only effective treatment.
Surgery is needed only if the cataracts are causing problems and generally results in an improved quality of life.
Cataract surgery is not readily available in many countries, which is especially true for women, those living in rural areas, and those who do not know how to read.
Refraction Test Each refraction test is provided as part of a regular eye examination.
This test reports your eye Yamout Optical Center will do and provide you with the prescription you demand in your glasses or contact lenses more information.
20/20 vision" redirects here. For other uses, 20/20 vision is a term for visual acuity in which the numerator refers to distance and the denominator refers to the size
"6/6" redirects here.
Visual acuity
Medical diagnostics
Snellen chart: rows of uppercase letters, the top row contains a very large 'E' and the size of the letters decreases with each row that follows.
A typical Snellen chart that is frequently used for visual acuity testing.
Visual acuity (VA) commonly refers to the clarity of vision. Visual acuity is dependent on optical and neural factors, i.e., the sharpness of the retinal focus within the eye, (ii) the health and functioning of the retina, and (iii) the sensitivity of the interpretative faculty of the brain.
