Blind visually impaired optical low vision aids questions

The most essential sensory organ gifted to humans to see the world is the eyes. But there are some reasons due to which the vision of an eye alters, which include aging, injury, infections, the shape of the eye, cataract, placement of retina, the focus of light on the retina, and many more. These reasons cause visual impairments to the eyes.

What is Visual Impairment?

The impairment is usually related to age that cannot be corrected by prescription glasses, contact lenses, medicine or even surgery; this problem eventually causes a decrease in the vision of the eyes, which is termed as Visual (Vision) Impairment.

Affecting a lot of people across the globe, visual impairment ranges from low to severe; it also causes impediments in normal daily activities where walking, writing, reading or driving becomes almost an impossible or challenging task.

Vision Problems:

Vision problems, also termed as refractive errors, also arise due to the shape of the eye, which prevents a person from focusing well, and it is the primary cause of vision loss worldwide. Also, due to protein clumping and tissue breakdown, clouding or transparency loss occurs in the lens of the human eye. Its symptoms consist of blurred vision or double vision and sensitivity to light and glare. There are several reasons for cataracts, together with aging, cortisone medication, and some other diseases like trauma, diabetes, etc. Most people are affected by cataracts during their old ages.

Low vision aids are classified into two types-

• Optical Aids
• Non-Optical Aids

Low Vision Aids – Optical Aids

Depending upon how severe the visual impairment is, the optical aids for low vision can range from magnifying reading glasses to small telescopes. Low vision devices are not made for all purposes. Instead, they are built for definite use only like watching movies, another for reading purposes, and yet another for some other works.

Optical vision aids are of three types-

• Distance optical aids
• Intermediate distance optical aids
• Near optical aids

Some of the remedies to Vision Impairment are listed below-

• Evolving technology has made things much easier for humans, as many low vision support such as magnifying glasses or telescopes etc., benefit visually impaired people to live a normal and healthy life.
• A system of writing termed as Braille contains characters made up of raised dots also helps blind people to read and write. Low vision or blindness doesn’t matter when knowledge is the key to living a good life. Optical and non-optical aids help people with low vision enhance their quality of life.

Important Questions on Blind Visually Impaired Optical Low Vision Aids

1) What is Visual Impairment?

The impairment is usually related to age that cannot be corrected by prescription glasses, contact lenses, medicine or even surgery; this problem eventually causes a decrease in the vision of the eyes, which is termed as Visual (Vision) Impairment.

2) Which eye surgery is best for Astigmatism?

Astigmatism is basically a refractive error not an eye disease; which can be cured by Lasik (laser-assisted in situ keratomileusis) surgery. Lasik surgery test provides 99.5% precise results.

3) Explain what myopia is, and how it can be corrected.

The inability of the eye to focus on distant or far objects is called myopia, which is also termed as near-sightedness. This defect of near-sightedness occurs when light from distant objects refracts more than the required limit. The ability to view distant objects requires less refraction of light. If the cornea swells more than its normal curvature, it results in more refraction of light than usual. This causes the images of distant objects to form, at a position in front of the retina. Also, if elongation of the eyeball takes place in the horizontal direction then it causes the images of distant objects to form in front of the retina. Therefore, the image is not focused on the light-detecting nerve cells on the retinal surface, where the image was supposed to be focused. Hence, this causes a blurry image on distant objects on the retina. And this defect is eventually named myopia.

Correction – The cure of myopia is to equip the eye with a concave lens, which is also called diverging lens. This diverging lens will diverge the light and make it converge on the light-detecting nerve cells on the retina, with the help of the eye lens. Hence, the image will be produced on the retina.

4) Explain what hypermetropia is, and how it can be corrected.

Hypermetropia which is also termed as Farsightedness, occurs because of the decrease in the size of the eyeball as a result of which the image of the objects is formed beyond the retina. Another reason for the cause of hypermetropia is the thinning of the eye lens due to which it lacks the efficiency to bend the rays of incoming light on the retina. A person suffering from farsightedness can see the far objects clearly, but finds difficulty in seeing the nearby objects clearly.

Correction – To cure hypermetropia we can equip the eye with a converging lens that is also known as convex lens.

5) What is Astigmatism?

Astigmatism is a refractive error which is caused by the irregularities in the shape of the cornea. Due to this disorder, the human eye fails to focus the light equally on the retina which causes blurred or distorted vision. This error can develop gradually in life or it may be present at the time of birth. Astigmatism is not an eye disease or eye health issue, it is just a refractive error.

6) What is Presbyopia? How is it corrected?

A common defect of vision, which generally occurs at old age is termed as presbyopia. Presbyopia is the gradual loss of the eyes’ ability to focus on nearby objects. A person suffering this defect is incapable of seeing nearby objects clearly and distinctly. The near point of a presbyopic eye is greater than 25 cm and it gradually increases as the eye becomes older. This defect can be corrected using bi-focal lens.

7) What are the symptoms of presbyopia?

Presbyopia grows gradually, its signs and symptoms can be first noticed after the age of 40, which are-

• Strain in the eyes after reading or doing close-up work
• Difficulty in reading smaller prints and letters
• Blurred vision at normal reading distance

8) What do you mean by visual defects?

A visual defect is a damage due to which a person lacks the ability to see the far-off or nearby objects clearly.

Some of the common visual defects are listed below-

• Myopia
• Hyperopia
• Astigmatism
• Ametropia

9) What are the different types of Astigmatism?

Basically, there are three types of astigmatism:

• Myopic astigmatism
• Hyperopic astigmatism
• Mixed astigmatism

10) How to cure myopia and hypermetropia naturally?

Some natural treatments of myopia and hypermetropia are-

• Protect your eyes from the sun
• Healthy diet
• Reduce the work that causes strain in your eyes
• Usage of good lighting
• Regular check-up of eyes

Practice Questions

1. What is Braille?
2. Describe in brief various parts of the human eye and their functions.
3. What are the different types of optical aids?
4. Differentiate between myopia and hypermetropia.
5. Define visual impairment.

Suggested Videos

Stay tuned to BYJU’S and Fall in Love with Learning!