Visual impairment

“ Good vision is a priceless gift. Yet each year many Americans needlessly lose vision as a result of diseases and accidents whose sight-destroying effects could have been prevented.
Regular eye examinations by an eyecare professional can often avert the tragedy of visual loss. While a checkup will usually show that our eyes are healthy, we may also receive early warning of a serious eye disease requiring treatment. Diabetic eye disease, for example, is a leading cause of visual impairment. ”

“ Health officials have identified the most significant and preventable threats to vision. According to the Department of Health and Human Service's Healthy People 2010 report, visual impairment represents one of our country's 10 most frequent causes of disability. ”

“ Men and women whose jobs require them to work with chemicals or machinery are at increased risk of eye injury. Macular degeneration takes a dramatic toll on the vision of people aged 60 and over, causing severe visual impairment and even blindness in its victims. ”

“ Several demographic groups are at higher risk for visual impairment, including teenagers, diabetics, Hispanics, African Americans, and the economically disadvantaged. Older Americans are more susceptible to eye conditions such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Children need regular vision screenings because vision disorders left untreated during childhood can lead to permanent visual impairment during adulthood. Still, eye disease knows no bounds, and every American should take steps to protect his or her eyesight. ”

“ By learning the early warning signs of eye disease, practicing eye safety, and having regular eye examinations, we can prevent some of the most common forms of visual impairment and blindness. Many eye disorders can be corrected or alleviated with prompt professional care. ”

“ For the more than six million Americans who suffer severe visual impairment, merely crossing the street may be a borrowing experience. This is especially true for the one-half million of our citizens who are legally blind and whose skill and resolve are tested daily in the traffic of our busy cities. ”

“ Children also need early and regular eye examination. Even the seemingly healthiest child may have an unsuspected visual problem that needs prompt attention. A routine checkup can identify such disorders in time for effective treatment, sparing the child a lifetime of visual impairment. ”

“ This common disease affects the retina, the part of the eye that helps to produce sharp, central vision required for activities such as reading and driving. AMD causes a loss of this clear, central vision; in some cases, vision loss is rapid and dramatic. The risk of AMD dramatically increases after age 60. It is estimated that this disease already causes visual impairment in approximately 1.7 million of the 34 million Americans now older than 65. As these numbers continue to grow, researchers are working to find the cause of, and develop treatment for, this debilitating disease. ”

“ During this year's observance, let us renew our commitment to fighting the causes of visual impairment and to supporting good eye health. I encourage all Americans to learn more about ways to prevent eye problems and to help others maintain the invaluable asset of eyesight. ”

“ People with AMD and its accompanying visual impairment often cannot perform daily activities such as reading the newspaper, preparing meals, or recognizing faces of friends. The inability to see well affects routine activities and social interactions and can lead to a loss of independence. ”

“ Protecting the eyes from injury is another important way to prevent visual impairment and even blindness. Safety glasses, goggles, or face shields should be worn in hazardous situations at work and while participating in potentially hazardous sports. ”

“ Fully to understand the mechanism for its regulation would carry us far toward an understanding of the causes of glaucoma. Normal [Pg 10] tension is maintained with a continuous flow of fluid into the eye and a corresponding outflow. Complete interruption of the nutritional stream would be speedy death; partial interruption may be held responsible for most of the visual impairment and pain of glaucoma.
The balance of intra-ocular pressure is not maintained by the slight distensibility of the sclero-corneal coat. Increased pressure does not open new channels for the escape of intra-ocular fluid ”

“ Due to hereditary and prenatal factors, from a very early age, many children are at high risk for potentially severe eye diseases, including retinopathy of prematurity (ROP) , amblyopia, and congenital glaucoma. One in four kids will develop myopia as teenagers. Children need regular eye care from birth to prevent and treat conditions that lead to visual impairment and blindness. ”

“ H54.3 Unqualified visual loss, both eyes Visual impairment category 9 in both eyes. H54.4 Blindness, one eye Visual impairment categories 3, 4, 5 in one eye [normal vision in other eye] H54.40 Blindness, one eye, unspecified eye H54.41 Blindness, right eye, normal vision left eye H54.42 Blindness, left eye, normal vision right eye H54.5 Low vision, one eye Visual impairment categories 1 or 2 in one eye [normal vision in other eye] . ”

“ Pupils entering our schools come to us with good eyes, but if they stay with us till the end of the course, GO to 70 per cent, of them will leave us with but two thirds normal visual acuity or less. Most of this loss of vision is caused directly by the strain put upon the eyes in reading, writing and drawing. ”

“ Persons, before submitting themselves into the hands of opticians, should know that they are not suffering from any incipient disease of their eyes. I do not, for a moment, claim that a practical optician cannot give you a pair of glasses which will make you see—he does nothing more than hand you a number of pairs of glasses and you select the one pair which you think answers the purpose. How can anyone but a medical man know that the impairment of vision does not arise from diminished sensibility of the retina? ”

“ There is hope as well for people who suffer from low vision. Affecting 1 in 20 Americans, low vision is an impairment that cannot be corrected by standard glasses, contact lenses, medicine, or surgery, and interferes with one's ability to participate in everyday activities. While it can occur in people of all ages and backgrounds, low vision primarily affects the growing population of people over 65 years old; other higher risk populations, including Hispanic and African Americans, are more likely to develop low vision at an earlier age. ”

“ The commonest visual defects are, first, inflammation of the cornea, or imperfections of the lens—the cornea is often so scarred as to make vision imperfect; second, myopia, or progressive shortsightedness, a condition in which the axis of the eye gradually grows longer. This lengthening is accompanied by stretching of the eyeball, and such children always run the risk of the inner and most important part of the wall of the eye, the retina or nerve layer, being torn away, and blindness resulting. ”

“ In this way it has happened historically that the first cases of special disability in reading and spelling among school children have been reported by ophthalmologists, to whom they were taken for examination of the eyes. Parents naturally sought the expert who knows eyes in such cases, for to one who has not studied the psychology of reading, it appears that a person “reads with his eyes” only.
The visual defects which may most commonly interfere with the mastery of the mechanics of reading are myopia, hyperopia, astigmatism, cataract, muscle-weakness, diplopia, and anomalies of the retina. ”

“ This strain, when it is habitual, leads to all sorts of abnormal conditions and is, in fact, at the bottom of most eye troubles, both functional and organic. The discomfort and pain may be absent, however, in the chronic condition, and it is an encouraging symptom when the patient begins to experience them.
When the eye possesses central fixation it not only possesses perfect sight, but it is perfectly at rest and can be used indefinitely without fatigue. It is open and quiet; no nervous movements are observable; and when it regards a point at the distance the visual axes are parallel. ”

“ The elderly and the young have a special need for periodic eye examinations. A number of blinding diseases strike more often in later years. With early warning of eye disease and proper treatment, older people could be spared visual handicaps which threaten their independence and limit their enjoyment of life. ”

“ Even if the doctor says this girl is sound and strong, her early months of college labor should be carefully watched. Above all, her eyes should be seen to, because in my experience some unsuspected disorder of vision has been fruitful of headaches and overstrain of brain, nor is it enough to know that at the beginning her eyes are good. Extreme use often evolves practical evils from visual difficulties at first so slight as to need or seem to need no correction. ”

“ It is they, above all, who will publish the glad tidings they and the school children under twelve, who having, as a rule, not accustomed their eyes to glasses, and being free from the misconceptions that handicap older patients, respond with incredible rapidity to the new methods— methods as simple as they are effective, and both preventative and curative of visual defects. ”

“ No matter how much the sight may have been impaired by sun-gazing, or how long the impairment may have lasted, a return to normal has always occurred; while prompt relief of all the symptoms mentioned has always followed the relief of eyestrain, showing that the conditions are the result, not of the light, but of the strain. Some persons who have believed their eyes to have been permanently injured by the sun have been promptly cured by central fixation, indicating that their blindness had been simply functional. ”

“ Among the many ocular problems of railway employees those relating to deficient color-perception are of great importance, but equally great are those regarding presbyopia or the failure of visual acuteness after 40 or 45 years of age, and especially should the diagnosis of right-eyedness or left-eyedness be held of prime necessity. The left hand may be allowed, somewhat against nature, to manage the throttle-lever, but the right eye must be the absolute judge of signals, etc. ”

“ By making the patient more comfortable glasses do often improve his mental condition, but since they cannot relieve the mental strain that underlies the visual one, they cannot improve it to normal and by confirming it in a bad habit they may make it worse. ”

“ I have seen an Oxford [283] and also a London oculist, who have both examined the eye and pronounce the sudden seizure to be one of serous effusion upon the retina. It seems probable that the impairment of vision will be permanent, and so prevent all operative work where any delicacy is required. The blindness is so complete, that if I look about an inch below the electric light placed at a distance of a very few yards, I am not able to perceive any luminosity. Meanwhile, I have to wear the darkest of possible goggles, and generally to live the life of a blind man. ”

“ But human beings are often called to still greater trials—to total loss of sight—in other words, to perfect blindness. This calamity results from many causes; for example, the cornea may become so opaque as to be incapable of transmitting rays of light into the interior chamber of the eye; or the crystalline lens, also, may become opaque (cataract;) disease of the iris, attended by closure of the pupil, will produce blindness, as will also paralysis, or loss of energy, in the retina or optic nerve, (Amaurosis or Gutta serena.) ”

“ In double hemiopia there is every reason to believe that not only the sensation of light must go, but that all memories and images{112} of a visual order must be annihilated also. The man loses his visual 'ideas.' Only 'cortical' blindness can produce this effect on the ideas. Destruction of the retinæ or of the visual tracts anywhere between the cortex and the eyes impairs the retinal sensibility to light, but not the power of visual imagination.
Fig. 46.—Fibres associating the cortical centres together. ”

“ Sight is a precious gift that enables us to experience the wonder of the world around us; but few of us think about what we would do if we lost our vision. Unfortunately, millions of Americans must face this challenge because of conditions like cataracts, glaucoma, diabetic eye disease, or age-related macular degeneration. ”

“ Thanks to vision research, effective treatment is now available to many people whose sight is threatened by eye disorders. But the greatest medical benefits generally go to those who get the earliest warning of serious eye disease. For them, there may be an opportunity to stop the disease before it has caused significant visual loss.
Middle age is a particularly good time for a person to take advantage of the protection that regular eye examinations can offer. ”

“ Except in extraordinarily rare cases blindness is curable.” In fact, unless the eyeball has been removed from the head, I should be unwilling to set any limits whatever to the possibility of relieving this greatest of human ills, for I have never seen a case or injury or disease of the eye which was sufficient to prevent improvement of vision. In all cases of blindness, whatever their cause, a mental strain has been demonstrated, and when this strain has been relieved perception of light has always been obtained. ”

“ It is easy to detect color blindness by simple tests.
So great is the importance of good vision in school work and the later work of life, that every teacher should know how to make simple tests to determine visual defects. Children showing any symptoms of eyestrain should be required to have their visual defects corrected by a competent oculist, and should be warned not to have the correction made by a quack. There is great popular ignorance and even prejudice concerning visual defects, and it is very important that teachers have a clear understanding of the facts. ”