The Conservation of Vision – A Study on Eye Care

Good vision is essential for success in most occupations and for the enjoyment of the beautiful and interesting things of life. Uncivilized man was dependent upon acuity of vision for his subsistence and even for life itself, and we receive most of our education through our eyes, by means of observation, printed words, and pictures.

The eye is an extremely efficient instrument, functioning almost continuously to provide clear vision for close work in school, office, or shop. In so doing it acts with surprising rapidity, performing upwards of 1,000 movements in 5 minutes of reading. It has been estimated that one-fourth of the daily energy expenditure of persons in sedentary occupations is utilized for the purpose of seeing.

Physiologically the eye is a mechanism, much like a camera, which brings the rays of light to focus upon light-sensitive nerve endings in the retina. These, in turn, transmit a stimulus to the brain where the visual image is perceived. In the lowest types of seeing animals the eye consists merely of-a few pigmented cells, sensitive to light, at or near the surface of the body, and connected with some simple nerve structure. In the higher forms of life these structures become more complex and connected with the brain. In addition to these more highly developed eyes, insects and worms retain some of the simple, supernumerary eyes. Most spiders, for example, have eight, and some worms four or more such eyes.

The simplest type of eye can perceive only light, but as one proceeds up the biological scale the visual apparatus becomes, more complex and begins to perceive size, shape, distance, and color. Since acute vision is an asset in the struggle for existence, the animals with the most efficient eyes tend to rise in the biological scale.

Until recently, biologically speaking, man lived out of doors and used his eyes chiefly for distance vision. Some change of focus was necessary, but the demands made upon the visual apparatus were but a fraction of what they have been since he changed his mode of living. Several million years of reading the printed page may bring about a better adaptation of these outdoor eyes to the manner in which we now live.

The Cause and Prevention of Blindness
One of the greatest calamities that can befall one is blindness. The occasional genius, such as Milton or Helen Keller, can rise above this calamity, but most persons are crushed by it. It has been estimated that there are 100,000 blind persons in the United States and that in at least 50 per cent of these cases the blindness was due to causes which could have been prevented. Of these causes, the most important are injuries, infections, poisons, and degenerative diseases.

Eye Injuries
Injuries constitute an important cause of blindness. Some of these for all practical purposes can hardly be called preventable, but the vast majority could be avoided with reasonable precaution. Children can be taught that they should not use sharp instruments and that certain toys and games are hazardous; industry can safeguard the vision of employees; and individuals can learn to take necessary precautions.

Most industrial eye injuries occur in such occupations as machine operating, chipping, grinding and polishing, mining and quarrying, riveting, welding and cutting, glass making, sand blasting, and woodworking operations. In these and other occupations in which fragments of metal, wood, or stone may be thrown about, goggles or masks should be worn. The Chicago Division of the American Steel and Wire Company reports that eye injuries resulting in total loss of vision were reduced from 1 per 643 employees to 1 per 2,700 employees and that the reduction in partial loss of vision was from 1 per 750 employees in last decade. This reduction was the result of the use of goggles and the adoption of other protective devices. Injuries on the farm and in many other areas could likewise be greatly reduced by reasonable care and the use of protective goggles.

First Aid in Eye injuries
Cleanliness is of the greatest importance in the care of eye injuries. A slight scratch on the surface of the eye may become so seriously infected that the eyesight is lost. The tissues of the eye are extremely delicate. For this reason expert medical attention should be secured whenever there is an injury to the eye.

Cinders in the Eye
Dust, Cinders, and other small particles of foreign material frequently lodge on the surface of the eyeball. The irritation thus produced results in a flood of tears which usually wash the offending particle away. Occasionally, however, such particles become lodged under a lid and for this or some other reason refuse to be dislodged. In such cases closing both eyes for a few moments without moving the eyeball leads to the accumulation of tears so that with the opening of the eyes the particle may be flushed out. Rubbing of the eyes irritates the tissues and embeds the particle.

Cosmetics Dangerous to Eyes
Among the cosmetics offered for the enhancement of beauty are dyes for eyebrows and eye lashes. Some of these contain chemicals which are injurious to the delicate structure of the eye; hence, their use is distinctly hazardous.

Eye Infections
Mild infections of the eye, such as those which are frequently accompany common colds; usually clear up with simple treatments. The more severe infections, on the other hand require medical attention. These may be acute and self limited or they may be due to serious disease, such as trachoma or gonorrheal ophthalmic, which, if not properly treated, will result in blindness.

All infections of the eye are communicable and care is necessary if infection of others is to be avoided. An inflamed, granular condition of the margins of the eyelids and the development of sites are frequently associated with eye strain and with general ill-health. For such conditions a complete physical examination and a careful refraction are more important than local treatments.

Poisons a feet the vision
Among the poisons which may produce partial or complete loss of vision are tobacco, wood alcohol, and quinine.

Many persons use tobacco for years without any apparent effect upon visual acuity, but others are definitely harmed by it. The eyes tire easily, visual acuity becomes progressively diminished, color vision is lost, and use of the eyes causes severe headache. Such symptoms occur most commonly in pipe smokers, particularly if both tobacco and alcohol are used in excess. If tobacco and alcohol are discontinued completely, the symptoms usually disappear rapidly and vision returns to normal. Such loss of vision occurs most commonly in men who smoke half a dozen or more cigars a day or several ounces of pipe tobacco a week.

Quinine probably has caused more blindness than any other one drug. Ringing of the ears, headache, partial deafness, and dizziness are the common toxic symptoms produced by quinine. Less frequent but more serious is loss of vision, which may be partial and temporary or absolute for days, weeks, or life. Knowledge of the possibility of serious harm from the use of this drug should make people less willing to consume it, without medical advice, in various patent medicines for the treatment of colds, fever, and malaria.

Cataracts
Various changes which impair vision may occur in the eye during the later decades of life, but most common of these is a cloudiness of the crystalline lens or its capsule, called “cataract.” Occasionally this is due to injury or disease but the most common type is the senile cataract, the cause of which is not understood. In the past a cataract was considered a hopeless sentence to blindness for the rest of one’s life, but now useful vision can be restored in 97 per cent of patients by means of a simple but delicate operation.

Glaucoma is a serious eye disease which is responsible for one third of all blindness after forty years of age. Mechanically this is due to an increased pressure within the eyeball. This much we know, but since the basic cause for the increased pressure is not understood we do not have the key to its prevention. However, if glaucoma is recognized early and proper treatment instituted, its progress frequently can be arrested. The early symptoms are headache, pain in the eyes, halos surrounding lights, and rapid loss of vision. Although these symptoms may be due to other causes, their presence makes a careful examination by a competent physician imperative.

Eyewashes
Advertisements for eyewashes with fancy names suggest that these preparations should be used regularly if one desires bright, sparkling, healthy eyes. Eye specialists, on the other hand, never recommend such practices. Dust and dirt are constantly settling on the eyeball but nature removes them by maintaining a constant flow of tears which are gently carried over the eyeball by blinking of the lids. If there is unusual exposure to dust, smoke, or other irritating substances, a few drops of a saturated boracic acid solution may be soothing.