of senior citizens also increases. This means that the percentage of patients past the age of 40 will continue to rise. These people require a different approach in many phases of eye care and the diagnostic significance of tests varies considerably. Final prescriptions and recommendations to the senior citizen are based on the physical and mental changes that come with age, as well as the need.

The importance of the physical and visual history of a patient becomes greater with age, for the deficiency of the current visual mechanism often is a result of earlier injury, disease and general physical being. In dealing with aging individuals it has been learned that members of the patient's family can throw a great deal of light on the patient's history, especially in supplying needed details that are lost in the haze of the older individual's memory. A patient's occupation, hobbies and activities, although perhaps more restricted, take on increased importance after 40. In examining the aging person, details such as location and position of his work, distances and eye levels while engaged in the task are considered. In some cases, actual measurements of working distances are taken. In addition, lighting and general conditions are noted. The amount of fixed attention and prolonged eye use under various conditions are also considered, and often different types of lenses are prescribed for different kinds of visual tasks. It is not unusual for the aging person to require several different types of lenses in order to see more efficiently and comfortably in his varied occupations.

There are a variety of tests used to determine all aspects of the individual's visual acuity and general eye health. Included are external examinations, opthalmoscopic examinations for detailed inspection of the interior of the eye including particularly the lens, retina, nerve head, macular area and vessels; retinoscopy and subjective tests, in order to determine exactly what lenses are needed; phorias and ductions, which are prismatic calculations for correction of neuromuscular disabilities; and, specific nearpoint tests, which assume increased importance for the patient past 40.

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Many optometrists, in taking histories of patients, are surprised to learn that some patients have never had a physical examination, or perhaps haven't had one in several years. It is important to understand that the body is under constant duress and change. A person reaching 40 is at a turning point physically. By working with physicians and geriatric specialists, the optometrist has the opportunity to assist in preventive care. The optometrist is often consulted professionally before other symptoms of aging have appeared. Diseases of the heart and arteries, cancer, nephritis, diabetes and others are best controlled if discovered early.

Decreased vision is found more commonly in the older age groups, and according to Wick, (1960), "Optometry's forte for the older age group lies in helping to make this period of life more worth living. With the reduction of physical stamina, so common to this period, increased use of the eyes is the general rule. Much careless advice has been given to patients with regard to saving their eyesight. There are no statistical data to substantiate any theory to the effect that use of the eyes wears them out. This advice only serves to make visual hypochondriacs of otherwise normal patients".

TIPS TO THE AGING PATIENT

Because of a deficiency in both near-point and far-point vision, often the result of natural changes in aging, the senior citizen may require bi-focal or tri-focal glasses. In order to make the adjustment as quickly and conveniently as possible, optometrists will often make a series of simple suggestions:

1. Try not to look at your feet when walking.

2. When reading a newspaper, fold it into half or quarter size, move it, rather than tilt your head upward, until you can read comfortably.

3. Be certain that the lenses are in the right position by making sure the frames are properly adjusted.

4. Wear your bifocals continuously for the first week or two, even though you may not require them for all tasks.

CATARACT AND GLAUCOMA

In considering the problem of aging as related to vision, two pathologies of clinical importance should be noted. They are senile cataract and glaucoma.

The cataract is defined as "any opacity of the crystalline lens". Although there are other manifestations which occur in individuals of all ages, the "cataract" as we generally know it is primarily associated with senility.

The complaint found most frequently among patients suffering cataracts is "my vision blurs" .... "I can't see as well". The degree of loss depends on the nature, extent, and position of the cataract. In addition, there are other symptoms which include distortion of images, and a change in color values and hues.

Another symptom quite common is the development of "secondsight". This is a characteristic that the uninformed individual becomes quite proud of, because of a newly acquired ability to read or see at certain distances without his glasses. With the senile cataract, this is often the result of a change in the crystalline lens, which causes the eye to become more myopic or less hyperopic. In such cases, the loss of vision at other distances is often overlooked because of the "improvement” in reading.

Fundamentally the exact causes of the senile cataract are unknown. There are a number of suggested causes, including changes in permeability of the lens capsule, changes in the lens proteins, excessive efforts to accommodate, effect of radiant energy on the lens, inadequate nutrition, and systemic disorders such as Diabetes. Surgery at present is the only effective treatment for cataract. Glaucoma is defined by Duke-Elder (1941) as "that pressure which the tissues of the particular eye in question are unable to withstand without damage to their structure or impairment of their function." Of all ocular pathologies, glaucoma is most important to both the optometrist and ophthalmologist, because it is hardest to detect in early stages, and may eventually result in total blind

ness.

It is estimated that 1 per cent to 2 per cent of patients over the age of 40 have glaucoma, that there is three times as much simple

glaucoma as acute, that the greatest incidence of adult primary glaucoma occurs in the 60-70 group (although it should be investigated in persons over 40), that males are somewhat more prone to simple glaucoma than females, but females show a definitely higher incidence of acute glaucoma.

Acute glaucoma is seldom found in myopic patients, but chronic simple glaucoma has an incidence which is unrelated to refractive error.

It is generally agreed that heredity may play a role in glaucoma. In a report by Posner and Schossman (1949) of 373 patients with primary glaucoma, 51 had one or more relatives afflicted with the same disease.

Unfortunately, symptoms are not easily detected clinically, except in acute glaucoma where the patient may complain of such symptoms as pain or headache over the eye, visual disturbances or haziness, the seeing of halos around lights, and the seeing of flashes of light.

Other than from diseases, many studies show that loss of visual acuity occurs naturally with age. In the healthy normal adult this loss is very slight, but nevertheless a very real one that often interferes with the aging person's regular activities.

Along with age usually comes a steady decline in the ability of the eyes to resist glare. This creates a problem especially in night driving for a person over the age of 60.

CONTACT LENSES FOR THE OLDER PATIENT

The development of the micro-corneal (small) lens has inspired a great popularity in the wearing of contact lenses. Today, approximately 4 million persons are wearing them, as compared to less than 200,000 just six years ago. The majority of today's wearers are females, estimated to be about 60 per cent of the total. The great majority are also younger persons, and most are first attracted to contact lenses for cosmetic reasons. In males, it has been found that because of the wide field of vision and the safety and convenience values with contact lenses, they are used a great deal to advantage for sports. Aside from sports and cosmetic uses,

there are also benefits in wearing contact lenses for certain vision conditions. Those suffering from keratoconus, irregular astigmatism, corneal scarring, aniridia and monocular aphakia are offered an opportunity through contact lenses to find dramatic improvement not possible with ordinary glasses.

Of the patients coming to contact lens specialists, 47 per cent are under 25 years old, 45 per cent are between 25 and 40 years old, and only 8 per cent are over 40 years old. The lack of cosmetic incentive to improve one's appearance, a failure to appreciate the optical and physical advantages, and an unwillingness to be inconvenienced during the adaptation period, are no doubt prime reasons for the lack of popularity of contact lenses with older people. Another strong deterrent is the fact that many of these people are presbyopic, which requires glasses in addition to their contact lenses for near-point or reading vision. There are a number of types of bi-focal contact lenses now on the market, and others are in the process of being developed. It is hoped that eventually the advantages of bi-focal correction will be available in a generally acceptable contact lens.

The most spectacular use of contact lenses in later maturity occurs after cataract operations. They are generally superior to spectacle corrections for aphakic patients. Their greatest advantage lies in the fact that they practically eliminate all aberrations found with regular glasses, mainly because they move with the eye, rather than the eye moving behind the lens. From a cosmetic viewpoint, the contact lenses do not give the highly magnified eye appearance that the heavy-plus spectacles do, because of the latter's thick convex lenses. The thickness and weight of aphakic spectacle corrections often cause discomfort to older patients, especially during warm weather. Contact lenses for these same people are light in weight, and found to be comfortable once the patient has become adapted to them. Generally, the older aphakic patient becomes adapted to contact lenses faster than the young person, probably because of reduced corneal sensitivity from the incidental severing of some of the corneal nerve fibers during the cataract operation.