People may suffer from visual impairment even though their eyes are perfectly normal. Such loss of vision may result from neurological impairment.

Vision is the combination of image formation and perception of various attributes of the image by the brain. When the brain is not able to perceive images or various attributes of images, the patient may suffer from neurological impairment of vision. Such impairment owes its origin to the nervous system.

Causes of Visual Impairment:

There are various areas in the brain that process some or the other attribute of the image that has formed on the retina. Occipital cortex, the area situated at the rear side of the brain is a very important site. It is responsible for processing visual stimuli and allowing people to make an idea about shape, distance, movement, color, etc. The severity of loss of vision depends on the extent and location of damage in the brain.

Neurological loss of vision may result from acquired brain injury, difficulties with visual perception, impairment in coordination of the eyes, etc. All these may stem from damage areas in the brain that are responsible for vision. There are many areas in the brain that are responsible for vision.

These areas can get damaged from various accidents like:

Stroke: If a person suffers a stroke, a part of his or her brain is likely to get damaged due to a haemorrhage or a blocked blood vessel.

Traumatic Brain Injury: A traumatic brain injury such as in a car accident or a violent fall can damage visual perception of the brain.

Infections: Infections such as meningitis attack the brain and may impair various areas of it.

Lack of Oxygen: People may suffer from lack of oxygen if they experience accidents like a near-drowning episode or a heart attack or something else, which has the effect of interrupting blood flow to the brain.

Diseases: Diseases such as brain tumors, multiple sclerosis etc. can precipitate neurological vision loss.

Symptoms of Visual Impairment:

Symptoms of neurological vision loss depend on the type of vision impairment and the location of damage in the brain. It may include:

Blurry vision: In Blurry vision, a person will not see things clearly or may see something in light but find it difficult to see them in dim light.

Double vision: In double vision, the patient sees a single object as two and cannot merge them as one.

Problems with depth perception of objects

Problem with bright light: In this type of problem, a person experiences difficulty seeing an object in a bright light. One may also feel pain or discomfort in the eye in bright light.

Difficulty with interpreting the object the person is looking at

Partial loss in the visual field: In this problem, half of the visual field in each eye is missing.

Treatment of Visual Impairment:

There is hardly any treatment for such vision loss since the rectification of visual acuity is of no help. Depending on the location and degree of neurological impairment, vision may improve over time. Some children with acquired brain injury or impairment in the coordination of the eyes and difficulties with visual perception also tend to improve with age.

Conclusion:

This is a type of vision loss where glasses, contact lenses, surgeries, or eye drops are not going to help. Such vision loss is usually permanent. Children with similar symptoms need to be presented with pictures, bright light, etc., which may help to form an idea about the object.

Visual Impairment Related To Nervous System!

Night blindness is also called nyctalopia.It's a type of vision impairment. People with night blindness experience poor vision at night or in dimly lit environments. It is not a disease in itself, but rather a symptom of an underlying problem, usually a retina problem.

What Causes Night Blindness?
A number of eye conditions can cause night blindness, including:
1. Nearsightedness or blurred vision when looking at faraway objects.
2. Cataracts or clouding of the eye's lens.
3. Retinitis pigmentosa, which occurs when dark pigment collects in your retina and creates tunnel vision.
4. Vitamin A Deficiency
5. Zinc Deficiency
6. Dry Eyes
7. Diabetes

Are the Symptoms of Night Blindness?
The sole symptom of night blindness is difficulty seeing in the dark. You're more likely to experience night blindness when your eyes transition from a bright environment to an area of low light, such as when you leave a sunny sidewalk to enter a dimly lit restaurant. You're likely to experience poor vision when driving due to the intermittent brightness of headlights and streetlights on the road.

How can I Prevent Night Blindness?
You can't prevent night blindness that's the result of birth defects or genetic conditions, such as Usher syndrome. You can, however, properly monitor your blood sugar level and eat a balanced diet to make night blindness less likely. 

Orange colored foods are excellent sources of vitamin A, including:
1. Cantaloupes
2. Sweet potatoes
3. Carrots
4. Pumpkins
5. Butternut squash
6. Mangoes

What are the Treatment Options for Night Blindness?
The treatment will depend on its causes.
1. Nutrient deficiency (Vitamin A and Zinc) is the easiest to treat. 
2. If the cause is cataract, you can go for cataract surgery to remove the clouded lens and replace it with artificial intraocular lens. Vision is usually dramatically improved after surgery. 
3. For dry eye syndrome, lubricate your eyes with artificial tear drops as they provide instant relief. Just make sure that they are without preservatives. 
4. Diabetic retinopathy can be prevented with tight control over blood sugar, active lifestyle and good dietary habits.
5. As for retinitis pigmentosa, unfortunately there are no treatments available. Thankfully, new research is showing that vitamin A might have a slowing effect on the progression of this eye disease.

Night Blindness: Causes and Symptoms

While spectacles are a fashion statement for some people, for others they are an uncomfortable necessity. Though contact lenses may be a little more aesthetically pleasing they too can be quite uncomfortable and cannot be worn throughout the day. Thankfully, there is a third way to correct vision. Laser surgery or LASIK, it is a popular refractive procedure that can correct common vision problems, such as nearsightedness, farsightedness and astigmatism. This procedure aims at reshaping the cornea so that light entering the eyes can be focused onto the retina for the person to have a clearer vision. 

Laser surgery is pain-free and quick in most cases. Usually, it does not take more than 15 minutes to correct vision in both eyes. The results of this surgery can be seen in as little as 24 hours. 

The first step of laser surgery to correct vision is to create a thin, circular flap in the cornea. This is then folded back to access the stroma or underlying cornea. An excimer laser is then used to remove some of the corneal tissue. For people suffering from nearsightedness, the cornea is flattened while for people suffering from farsightedness, the cornea is made steeper. In cases of astigmatism, an irregular cornea is smoothened. Once the correct gradient has been achieved the corneal flap is put back into place and the cornea is allowed to heal naturally. There are no stitches or bandages required in a laser eye surgery. You may feel a temporary burning or itching sensation in your eyes immediately after the procedure. It is important not to rub your eyes or place any pressure on them. Your vision may also be cloudy or blurred for the first few hours. A doctor will usually advise you to rest for a few days after the surgery so that your cornea can heal properly. In a few days, your eyesight should stabilize, though, in a few rare cases, it may take a little longer. You should also avoid any form of strenuous exercising for a few days after the surgery. 

Though LASIK surgery has a very high success rate, there are very rare occasions where spectacles may still be needed even after the surgery. Thus LASIK is a choice of treatment for many who seek freedom from glasses.

LASIK - Say No to Boring Glasses! 

Visual impairment is a decreased ability to see to a degree that causes disabilities or problems, not fixable by usual means, such as glasses. Loss of vision may be acquired and develop suddenly. It may affect one or both your eyes.

What Causes Loss of Vision/Disability?

Loss of vision and disability can result from the following  

Clouding of normally transparent eye structures

Abnormalities in the retina

Abnormalities in the nerves carrying visual signals to the brain from the eyes

Changes in vision may also occur due to conditions like glaucoma, macular degeneration and diabetic retinopathy. 

Can Psychological Rehabilitation Help Manage Visual Impairment?

Vision loss and disability often interfere with one s functional ability in everyday tasks. Sometimes, the disability may be so devastating that it affects a person s mental health and behaviour. Psychological Rehabilitation is designed to help such visually impaired people deal with disability or impairment. 

Psychological rehabilitation involves a wide range of methods that aims to restore functioning after loss of vision, just as physiotherapy restores functioning after an injury or stroke. The program allows patients to continue living independently and maintain their quality of life despite vision loss. 

Complete or partial loss of vision can jeopardize one s career   you may not be able to continue with your job due to the disability.  Many people suffer psychological and physical challenges, which force them to escape the outside world. Psychological rehabilitation helps in the following ways  

Helps individual understand and accept the disability, and find ways to cope with it

Motivates them in to keep trying

Cope with the pain and depression

Overcome feelings of fear or despair

Prevents the person from sinking into a state of self-pity, which may hinder recovery

Rehabilitation Psychology adopts a holistic and expansive approach to treat visual impairment. 




Loss of Vision & Disability - How Can Psychological Rehabilitation Help?

The most common vision problems are shortsightedness and farsightedness. Shortsightedness is when a person sees close objects clearly while distant objects appear blurry. It is more common than farsightedness and affects about 70% of the Asian population.

When there is a refractive issue, the prescription usually has a plus/minus with it and also a number. A  minus  symbol is used to represent shortsightedness; the greater the number of the glasses, the higher the shortsightedness. High myopia is a more severe form of shortsightedness where the power is -6.0 or higher.

Symptoms: 

As mentioned, the person will be able to see nearby objects but will have difficulty seeing far off objects.

Difficulty reading signs and boards
Squinting
Straining to reduce the strain on the eye
Tired and fatigue due to this eye strain, especially when in constant move like playing sports or travelling
How it happens?

Vision can be explained by a physical process where light passes through a lens and falls on the retina in the posterior portion of the eye where it forms an image. This is then sent to the brain where it is read and interpreted as a particular object. When the lens becomes elongated, the image that is formed is distorted in that it is formed in front of the retina and not on the retina. Though it gradually settles down with adulthood, in most cases, it progresses and requires corrective lenses. The corrective lenses ensure the image falls on the retina and visual perception is improved.

Treatment:

Corrective glasses are the most commonly used measure for nearsightedness. The lenses could be used either as spectacles or as contact lenses.
Laser surgery can also be used to correct the problem. A thin layer of the cornea is removed and the image formation is corrected.
Artificial intraocular lenses are also being used to treat this condition. They work like contact lenses and may need periodic replacement.
The most common technique, especially for high myopia is the use of surgery to correct the problem. This is a one-time correction and is a more durable solution than the earlier mentioned options.
Appropriate calculations are done to identify the lens to be used so that proper vision is restored.
Complications: 

Though not common, retinal detachment and variable postoperative refractive error can occur during the surgery.
It is very important to set realistic expectations with the patient in terms of what to expect before, during, and after surgery. If only one eye is going for repair, the chances of mismatch in vision could be present in the early stages. Being clear about what to expect will help in successful correction.

Myopia or Nearsightedness - How It Can Be Treated?

Cataract can be defined as the clouding of the natural lenses in the eyes. This is caused by the clumping of protein in the eye lens. Cataract is a common eye disorder and the leading cause of loss of vision in people who are past their fortieth birthday. Cataract can occur in one or both eyes. When diagnosed properly, cataract can be treated with surgery to prevent blindness.

Depending on where and how they develop, there are many types of cataract. The most common amongst these are:

1.        Subcapsular cataract

These occur at the back of the eye lens. Diabetic patients are very susceptible to this kind of cataract.

2.        Nuclear cataract

Yellowish-brown cataract that form in the center of the lens are called nuclear cataract. This is usually seen in cataract caused by ageing.

3.        Cortical cataract

Cataract in the lens cortex are known as cortical cataract. These are wedge shaped and whitish in color. Spokes protruding out of these opaque wedges can be seen moving towards the center of the eye.

4.        Congenital cataract

Though they are not common, babies can also have cataract. Cataract formed at birth or within the first year of a baby's birth are known as congenital cataract.

5.        Secondary cataract

Cataract is one of the known side effects of diabetes and glaucoma. Some steroids and medicines are also linked to cataract.

6.        Traumatic cataract

If your vision becomes cloudy years after an eye injury, it could be a traumatic cataract. It can take several years for this to happen.

7.        Radiation cataract

Exposure to radiation can also lead to cataract. This is seen sometimes in patients who have undergone radiation therapy to fight diseases like cancer.

Though the type of cataract might differ from person to person, the symptoms are usually the same. Some of the common symptoms of cataract are:

1. Blurred vision
2. Reduced night vision
3. Increased sensitivity to light and glare
4. Seeing halos around lights
5. Colors appearing faded
6. Double vision

A reading test is the first step towards diagnosing cataracts. This is followed by tests to measure the eye pressure. Your doctor will also need to dilate the pupil to check the condition of the optic nerves and retina.

Surgery is the safest way to remove a cataract. Surgery is usually recommended when cataract begin inhibiting your daily life such as preventing you from driving, interfering with reading etc.
 
In most cases, this can be done as an outpatient procedure. The earlier it is diagnosed, the easier it is to treat. Hence, if you notice any of the symptoms mentioned above, get your eyes checked at once. The surgery is a day-care surgery only, so a person can go home the same day.

Is Your Vision Clouded? It Could Be Cataracts

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