Braille script - class-IX

Sarcoma is the cancer of connective tissues, lymphoma is cancer of lymphatic tissue, myeloma is the cancer of plasma cells. Whereas, glaucoma is a condition that causes damage to the eye's optic nerve and gets worse over time due to viterous humor not being drained and causing pressure on the eye ball.
Thus, the correct answer is option B.

• World Braille Day is annually celebrated on January 4, the birthday of Braille inventor, Louis Braille. 
• The day recognizes the contributions of Louis Braille in helping blind and visually impaired people to read and write. Hence, World Braille Day is observed on 4th January.
  So, the correct answer is '4th January'.

• Colour blindness is not really blindness it is the inability to see color. Red-Green color blindness is a sex-linked recessive disorder. 
• The gene for the color receptor is located on X chromosome any defect in this gene causes a person to lose his ability to see red and green. 
• For a colorblind person, red and green colors appear, Grey,

• Braille is a tactile writing system used by people who are visually impaired. It is traditionally written with embossed paper.
•  Braille users can read computer screens and other electronic supports using refreshable braille displays. 
• They can write braille with the original slate and stylus or type it on a braille writer, such as a portable braille notetaker or computer that prints with a braille embosser. Hence, the Braille script is A special type of script that is used by people who cannot see. 

The right optic tract carries information from the left visual field of both eyes. Damage to the right optic tract results in left homonymous hemianopia, meaning the patient cannot perceive images striking the left half of the retina in the left eye (which corresponds to the right visual field) or the right half of the retina in the right eye (which corresponds to the left visual field). Option B correctly describes the loss of the left half of the retina's input.

Night blindness is a vitamin deficiency disorder, whereas glaucoma, cataract, and hyperglycemia (often associated with diabetic retinopathy) are conditions related to eye diseases or systemic metabolic issues affecting the eye.

Myopia is a condition in which the light rays entering the eye converge in front of the retina instead of on the retina, for objects that are at a greater distance.

LASIK is a laser eye surgery which helps treat astigmatism, hypermetropia and myopia. It cannot treat colour blindness as it is not caused by lens defect of eye.

Sarcoma is a type of cancer that develops from certain tissues like bone or muscle.

Nyctalopia also called night blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition (for example, a lack of vitamin A). It can be described as insufficient adaptation to darkness.
Rhodopsin helps seeing lighted things and is synthesized in the presence of vitamin A (retinol). Its deficiency leads to lack of clear vision during night.

The lens capsule is attached to the ciliary body by a ligament and serves to refract and focus light rays on the retina. Loss of flexibility with age causes presbyopia, characterized by focusing of the image behind the retina. Likewise, too short eyeball causes hyperopia (long-sightedness). In both cases, distant images are clear but the nearby images are blurry and the condition is termed as hypermetropia. 

The lens capsule is attached to the ciliary body by a ligament and serves to refract and focus light rays on the retina. Loss of flexibility with age causes presbyopia, characterized by focusing of the image behind the retina. Likewise, too short eyeball causes hyperopia. In both cases, distant images are clear but the nearby images are blurry and the condition is termed as hypermetropia.

The lens capsule is attached to the ciliary body by a ligament and serves to refract and focus light rays on retina. Loss of flexibility with age causes presbyopia, characterized by focusing of image behind the retina. Likewise, too short eyeball causes hyperobia. In both cases, distant images are clear but the nearby images are blurry and the condition is termed as hypermetropia. This makes option C correct and option D incorrect. On the other hand, myopia or nearsightedness is caused by elongation of eyeball which results in focusing of image in front of retina. Thus, the distant images are blurry but the nearby images are clear. This makes option B incorrect. Cataract is characterized by presence of opaque lens, incapable of transmitting the light rays and is corrected by surgical replacement of lens with artificial lens. This makes option A incorrect. Correct answer is C. 

The lens capsule is attached to the ciliary body by a ligament and serves to refract and focus light rays on the retina. Loss of flexibility with age causes presbyopia, characterized by focusing of the image behind the retina. Likewise, too short eyeball causes hyperopia (long-sightedness). In both cases, distant images are clear but the nearby images are blurry and the condition is termed as hypermetropia.

Myopia is nearsightedness and short-sightedness, is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it, causing the image that one sees when looking at a distant object to be out of focus, but in focus when looking at a close object.
It can be corrected by the use of corrective lenses that have a negative optical power i.e., concave glasses which compensates for the excessive positive diopters of the myopic eye.
So, the correct answer is option A.

Presbyopia is an age-related condition where the eye loses the ability to focus on near objects, requiring bifocal lenses to correct both near and distance vision.

Cataract is a problem of an eye. It arises in old age it is caused due to the formation od an opaque membrane over the eyeless. This member reduces the intensity of light falling or the eye lens. Cataract is corrected by surgical replacement of lens with the artificial lens. 

Conjunctivitis is an infection of the eyes. In this the conjunctiva which is the thin skin present on the front of the eye becomes swollen. It may affect one or both eyes. The eyes become red and sticky or watery that causes eye surface irritation. So, the correct answer is option C.

The shape of the lens of the eye is regulated by the suspensory ligaments and ciliary body. The focal length is adjusted by their regular contraction and relaxation. Myopia is a condition of the eye where light focuses in front, instead of on the retina. This causes distant objects to be blurry while close objects appear normal. Myopia is corrected by using a concave lens. This defect arises either by elongation of the eyeball of the excessive curvature of the cornea. In this far point of the suffering myopia cornea close to the eye.

Loss of flexibility in crystalline lens with age causes presbyopia which includes focusing on the image behind the retina. Both hypermetropia and presbyopia cause the formation of blurry nearby images which can be corrected by wearing of the convex lens. Myopia is caused by elongation of the eyeball which results in focusing of the image in front of retina and forms blurry distant images. Myopia is corrected using the concave lens. Glaucoma is caused by blockage of tiny ducts that drain the excess aqueous humor from anterior compartment causing a buildup of aqueous humor. This causes compression of the arteries that serve the nerve fibers of the retina due to increased pressure. The death of nerve fibers due to lack of nutrients makes the person partially blind. Thus, the correct answer is option D.

Presbyopia is the defect of old age in which both the near and distant objects are blurred The elasticity of lens of eye decreases hence the accommodation power diminishes.

• Convex lens converge the light rays and decrease the focal length.
• Concave lens diverge the light rays and increase the focal length.
• Cylindrical lens have curved surfaces that focus the light rays to a point.

• Rods: These are the photoreceptor cells that contain rhodopsin pigment and associated with scotopic vision of eye i.e. vision under low light.
• Cones: These are the photoreceptor cells that contain iodopsin, porpyrosin and cyanopsin pigments. These cells are associated with the daylight vision and colour vision of eyes.

• Cones are the photoreceptor cells that contain iodopsin, porpyrosin and cyanopsin pigments. These cells are associated with the daylight vision and colour vision of eyes.
  
• Rods are the photoreceptor cells that contain rhodopsin pigment and associated with scotopic vision of eye i.e. vision under low light.
• Rhodopsin or visual purple (derivative of vitamin A) is a photopigment in the rods that are associated with scotopic vision of eye i.e. vision under low light or dim light.

The old person requires spectacle for both nearsightedness and farsightedness which is found in presbyopia for correcting near vision and far vision both.

Presbyopia is a condition of consisting of nearsightedness, farsightedness, and astigmatism. The condition is common in old age because of hardening of eye lens which results in focusing of light behind the retina for closely placed objects.

• Braille is named after its creator, Louis Braille, and consists of raised dots arranged in "cells."
•  A cell is made up of six dots that fit under the fingertips, arranged in two columns of three dots each. 
• Each cell represents a letter, a word, a combination of letters, a numeral or a punctuation mark. Hence, In braille script, letters are formed with 6 embossed dots.

Helen Adams Keller was born a healthy child in Tuscumbia, Alabama, on June 27, 1880. At the age of 19 months, Helen became deaf and blind as a result of an unknown illness, perhaps rubella or scarlet fever. As Helen grew from infancy into childhood, she became wild and unruly.As she so often remarked as an adult, her life changed on March 3, 1887. On that day, Anne Mansfield Sullivan came to Tuscumbia to be her teacher. Anne began her task of teaching Helen by manually signing into the child's hand. Anne had brought a doll that the children at Perkins had made for her to take to Helen. By spelling "d-o-l-l" into the child's hand, she hoped to teach her to connect objects with letters. Anne took Helen to the water pump outside and put Helen's hand under the spout. As the cool water gushed over one hand, she spelled into the other hand the word "w-a-t-e-r" first slowly, then rapidly. Suddenly, the signals had meaning in Helen's mind. She knew that "water" meant the wonderful cool substance flowing over her hand. Quickly, she stopped and touched the earth and demanded its letter name and by nightfall, she had learned 30 words.

Trachoma is an infectious disease caused by bacterium Chlamydia trachomatis. The infection causes a roughening of the inner surface of the eyelids. ... Untreated, repeated trachoma infections can result in a form of permanent blindness when the eyelids turn inward. So, the correct option is :D" (Eye).

Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface. Nearsightedness also can be caused by the cornea or lens being too curved for the length of the eyeball.

Presbyopia is a condition associated with aging in which the eye exhibits a progressively diminished ability to focus on near objects. Loss of elasticity of the crystalline lens, changes in the lens curvature from continual growth and loss of power of the ciliary muscles may be the cause of presbyopia .

A cataract is a common eye condition, where the lens becomes progressively opaque, resulting in blurred vision, incapable of transmitting the light rays and is corrected by surgical replacement of lens with the artificial lens. Thus, the correct answer is option D.

Tight neck ties constrict the jugular vein. This constriction may raise blood pressure within the eye and cause an increase in intraocular pressure (IOP). The increased IOP may put tight neck tie wearers at risk for developing glaucoma.

Myopia occurs when the light is focused in front of the retina. It occurs because either the eyeball is too long, or because the cornea is too curved. People with short sight are not able to see distant objects clearly. Concave prescription lenses (called as minus lenses) are used to bend light rays slightly outwards. The light rays then have a greater angle to bend back to focus when traveling through the cornea and lens. As a result, the light rays focus further back on the retina.

Glaucoma is a group of ocular (eye) disorders resulting in optic nerve damage or loss to the field of vision, caused by a pressure buildup of the fluid of the eye. The increased pressure, called as intraocular pressure, can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, glaucoma will cause permanent loss of vision. Without treatment, glaucoma can cause total permanent blindness within a few years.

A cataract is a clouding of the lens in the eye, that affects vision. Most cataracts are related to aging. People with diabetes or those taking high doses of steroid medications have a greater risk of developing subcapsular cataract (the one that occurs at the back of the lens).
Thus, the correct answer is the option (C), 'Steroids'.

Hyperopia or hypermetropia, is a refractive error. Ideally, the cornea and lens, the two focusing structures in the eye, focus images directly on the surface of the retina. If the eye is too short, or the focusing power is too weak, the image is focused behind the retina. At the retinal surface, the image is blurred. Thus, the vision, too, is blurred.

Hypermetropia occurs when the light is focused behind the retina. So, the lens changes its thickness, which aims to bring the light into focus on the retina - a process is called as accommodation. But, people with long sight cannot accommodate fully and so the light does not focus sharply and vision is blurred. This occurs because either the eyeball is too short, the cornea is too flat or the lens cannot become round enough. The simplest, cheapest and safest way to correct long-sightedness is with glasses. 

Rhodopsin serves as a visual purple pigment of rod cells and is responsible for night vision. Rhodopsin deficiency causes night blindness. Myopia is caused by elongation of eyeball while shortening of eyeball causes hypermetropia. The cornea is the transparent anterior window of an outer layer of the eyeball and does not have rods. Thus, the correct answer is option D.

Myopia also known as nearsightedness or short-sightedness is a condition of the eye where light focuses in front, instead of on the retina. People having myopia can see close objects clearly, but objects farther away appear blurred. It occurs if the eyeball is too long or the cornea is too curved. So, the correct answer is option B.

Colour blindness and haemophilia are both X-linked recessive disorders. 

Presbyopia is caused by an age related process. It occurs due to a gradual thickening and loss of flexibility of the natural lens inside the eye. These age related changes occur within the proteins in the lens, making the lens harder and less elastic over time. Age related changes also take place in the muscle fibers surrounding the lens. Changes in the lens curvature progressively cause diminished ability to focus on near objects. 

The canal of Schlemm is a channel in the eye that collects aqueous humor from the eye and moves it into the bloodstream. If the canal is blocked, the pressure in the eye can increase, resulting in glaucoma. Glaucoma is a condition that causes damage to the eye's optic nerve. It is associated with a buildup of pressure inside the eye. The increased pressure, called as intraocular pressure, can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, glaucoma will cause permanent loss of vision. Thus, the correct answer is option D.

Cataract is due to clouding of the lens. Due to this, the lenses become opaque and the vision is impaired. In this condition, an operation is needed. Cataract is very common in old age.

• The Nemeth Braille Code for Mathematics is a Braille code for encoding mathematical and scientific notation linearly using standard six-dot Braille cells for tactile reading by the visually impaired.
•  The code was developed by Abraham Nemeth. The Nemeth Code was first written up in 1952. Different languages have different types of braille code like example :
• Unified English Braille (UEB) Code
• European Braille Code (EBU)
• Cyprus Braille Code. Hence, Unified English Braille (UEB) Code, European Braille Code (EBU), Cyprus Braille Code are Braille codes.

• Louis Braille was born in Coupvray, a small town about twenty miles east of Paris, on 4 January 1809.
• He and his three elder siblings – Monique Catherine (b. 1793), Louis-Simon (b. 1795), and Marie Céline (b. 1797)– lived with their parents, Simon-René and Monique, on three hectares of land and vineyards in the countryside.  Hence,    Louis Braille was born in Coupvray.

• A cell is made up of six dots that fit under the fingertips, arranged in two columns of three dots each. 
• Each cell represents a letter, a word, a combination of letters, a numeral or a punctuation mark. 
• The first ten letters of the alphabet are formed using the top four dots (1, 2, 4, 5). This results in 2*2*2*2*2*2=2^6=64 different patterns of raised/unraised dots. 
• But, according to the Braille description, we must eliminate one of these 64 possible patterns, because at least one dot must be raised. Therefore, there are 63 possible raised-dot patterns.

• Braille is a system of reading and writing by touch used by the blind. The basic Braille symbol, called the Braille cell, consists of six dots arranged in the formation of a rectangle, three dots high and two across. 
• Other symbols consist of only some of these six dots. It consists of arrangements of dots which make up letters of the alphabet, numbers, and punctuation marks. 
• The basic Braille symbol, called the Braille cell, consists of six dots arranged in the formation of a rectangle, three dots high and two across. There are no different symbols for capital letters in Braille. Hence, Capital letter does not have separate symbols in Braille Script

• Blind people can't physically hear better than others. 
• Yet blind people often outperform sighted people in hearing tasks such as locating the source of sounds. 
• So blind people may have lost their vision, but this leaves a larger brain capacity for processing the information from other senses. Hence, Virtually impaired people are less sensitive to touch and their hearing power is also very weak.

• Louis Braille was a French educator and inventor of a system of reading and writing for use by the blind or visually impaired. He excelled in his education and received a scholarship to France's Royal Institute for Blind Youth. 
•  He began developing a system of tactile code that could allow blind people to read and write quickly and efficiently. inspired by the military cryptography of Charles Barbier, Braille constructed a new method built specifically for the needs of the blind. 
• He presented his work to his peers for the first time in 1824. Hence, Charles Barbier was the inspiration for Louis Braille's invention of a 6 dot method for reading and writing for the blind.