Blindness -

Visual impairment is when a person has lost eyesight can not be corrected by using glasses or contact lenses

There are two major categories of visual impairment:

Vision or partial visual impairment - where the level of moderate vision loss

Extreme weakness of sight (blindness) - where the level of severe sight loss to the extent that the activities that depend on

Eyesight becomes impossible

How is the visibility measurement

There are two main areas seen them when they are measured to see someone:

Visual acuity - a central your vision, and is used to look at things in detail, such as reading a book or watching TV

Visual field - an ability to see around the edge of your vision when looking straight ahead

Snellen test

Snellen test measures the severity of your sight. Involves reading the letters off the table and that it becomes progressively smaller letters. This table is used during routine eye test.

After the test be given as a result consist of two numbers. The first number represents the distance from the table that you are able to read the letters it successfully. The second number represents the distance that should be someone with the vision of a sound to be able to read the table.

So if you give a degree of visual acuity 6/60, it means that you can read about after only 6 meters, which can be for someone who has a healthy sight reading distance of 60 meters.

Visual field test

During the visual field test will guide you to look straight ahead in the device while the lights flashed on and off in your peripheral vision. You will ask you to press a button every time you see the light. This would indicate any gaps in the field of vision you have.

Partial sight

Partial sight, or visual impairment, usually defined as:

• The existence of extreme poverty in visual acuity (3/60 to 6/60), but the presence of the entire field of vision, or

• A combination of moderate visual acuity (until 6/24) and the field of low vision or the presence of noise or blur in your central vision, or

• A unit relatively good eyesight (until 6/18), but a lot of the field of vision you have missing

Extreme weakness of sight (blindness)

The legal definition of extreme weakness of sight (blindness) is when "a person is too blind so he can not be doing anything for the sake of sight is necessary."

This usually falls into one of three categories:

• The existence of extreme poverty in visual acuity (less than 3/60) but having a full field of vision

• Having poor eyesight unit (between 60/3 and 6/60) and a sharp decline in the field of vision you have

• A unit eyesight medium (6/60 or better) very low visibility and field

Get help

There are support services and charities and devices that can help all of them to make life easier if you have a weakened vision.

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Does not mean you are no longer able to work just because you have a weakness in the vision. It can be for many people who are either visually impaired or blind continue to work in very difficult roles often with the help of assistive technology, training and support.

Leadership

If diagnosed with a case known to cause weakness in the vision, you have a legal duty to inform the agency market and the vehicles license. Failure to do so is a crime and can lead to a fine.

Who gets

The cause of most cases of visual impairment caused by aging. It is estimated that about 1 in 5 people over the age of 75 have some degree of visual impairment.

Some of the most common causes of visual impairment include:

• -aldmor age-related degeneration - which stops the central part of the part of back of the eye (macular, which plays an important role in the central vision) work properly

• cataracts - where they can be shaped cloudy patches on the eye lenses

• Glaucoma - where they accumulate fluid until the inside of the eye, and damage the optic nerve (which transmits information from the eye to the brain)

• Diabetic retinopathy - where damaged blood vessels that nourish the eye as a result of the accumulation of glucose

You could restore vision?

It depends on the underlying cause behind it.

You can cure cataract surgery, which usually lead to a partial improvement, at least in the vision. Read more about cataract surgery lens.

It is usually not possible to restore vision in cases of age-related macular degeneration, glaucoma and diabetic retinopathy

. However, there are many treatments that can prevent further damage vision, or at least slow down the development of this

Cases.