There are three basic groups of exercises. Each has its individual function and is done in a different way.
This is a group of simple eye exercises to improve vision, designed to relieve the strain and tension in an eye especially at the end of a hard day’s work.
These are an effective group of exercises designed to act on a particular muscle or group of muscles. They also help in coordinating the interplay between different muscles. Most need some mechanical device or instrumentation for the exercise. The selected exercises are based on an eye examination and evaluation of the muscle function and balance and are best administered by trained personnel. For this the group there are certain devices which may be taken home to further exercise the eye.
These are optical eye exercises to improve vision, designed to improve the optical function in a weak eye by stimulating it with a series of exercises based on intermittent light flashes. The instrumentation is sophisticated and functional.
Thus, it is correct to say that exercises can “improve” the eye, mechanically and optically. However, the exercises are not as simple as usually made out and are given by trained personnel on sophisticated machines—something quite understandable considering the immense complexity of nature’s greatest creation—the human eye.
What are the Group I “home exercises” for the eyes?
The exercises are designed to rest the eyes. For the sake of convenience the exercises have been condensed by using a computer into a compact eye exerciser.
The eye exerciser is very useful especially to those who wear glasses and to those who do long’ hours of near work. A few minutes once to twice a day is sufficient to keep the eye relaxed. It is essential not to strain while using the exerciser, for after all we want to reduce strain, not cause it, by the exercises.
What are the Group II exercises done to specially increase the power of the external muscles?
Most of the exercises are done with specific instructions, some simple, some complicated.
(1) The Synoptophore
This is the most complicated and the most versatile of all instruments, used both to find out muscular imbalances as well as to give exercise.
It can assess all 3 grades of binocular vision and has the ability to re-educate the patient in various visual exercises.
A small degree of squint can be treated on this instrument without the need for any surgery.
(2) The Cherioscope
This used to co-ordinate the eye and hand. The exercise provides a stimulus for better, more accurate vision in the eye whose vision is depressed (the correct medical term is suppressed). It can also be used to give variable exercises by increasing or decreasing the prismatic power.
It is an instrument which can be taken home for exercise by virtue of its simple design and portability.
(3) Pigeon-Cantonnet stereoscope
This is extermely useful to improve fusion especially in cases where the eyes are divergent or spread out. It also helps in fusion and prevents suppression of an eye and therefore increases it visual ability.
It is very versatile for giving exercises at home in selected cases. Properly handled it gives good results.
Basically this is an adaptation of the hand stereoscope or “Viewmaster” we have all used in childhood to see three dimensional views.
It is designed for home training and has the ability to treat muscular imbalance or accommodation-convergence imbalance. In certain cases of squint, exercises on this instruments can control the angle of deviation.
The Asher-Law has adjustable movements which can exercise one variable, say accommodation, without any change in other variables. It is very useful in children.
(5) Cruise stereoscope
This has the ability to increase the fusion capacity in a person. Using a graduated print test, progressively different slides are put in till the fusion capacity reaches normal.
(6) Remy separator
This is a very simple apparatus, designed to exercise divergence in a patient who has a tendency to turn his eyes in or converge excessively. Properly seen, with the eyes relaxed, the two images fuse.
(7) The diploscope
This is a device in which the eyes are taught to relax the accommodation, in those eyes where its excess has led to squint. It is also useful in those eyes where the eye tends to squint intermittently in a divergent or outward direction. It is a useful diagnostic instrument also and checks the capacity for binocular vision.
(8) Bar readers
These are meant for those patients whose convergence (eyes turning in for reading) and accommodation (increase in power of eye to change focus from distance to near) do not balance and in cases where the two eyes do not work in a proper binocular fashion. Here a bar is introduced between the print and the book, and unless both eyes see equally well, the words will not be read clearly.
(9) The RAF binocular gauge
The binocular gauge can test and exercise convergence and accommodation separately. It has a small scale which is useful to check the functional reserves.
A useful treatment both for diagnosis and treatment.
How do eye exercises improve the optical capacity of the eye?
The image seen by the brain is formed in the two eyes, which simultaneously perceive it and fuse it into a single entity, to give an impression of depth.
The optical image is important simply because it is the fusion mechanism which keeps the two eyes seeing parallel in an effort to maintain a single image.
Hence all optical exercises are designed on the three important pillars of binocular vision or grades of vision.
What are the grades of binocular vision?
Grade I: simultaneous perception: the ability to see an image simultaneously with both eyes, even if it is totally different.
Grade II: fusion: the ability to fuse two slightly disparate images into a coherent whole.
Grade III: stereopsis: three-dimensional depth perception. Stereopsis exists because two fused images are seen slightly differently in the two eyes simply because of the separation between the two eyes.
Thus the optical exercises are designed to help and improve binocular vision.
What exercises are used to improve visual power of an eye using optical methods? What is pleoptics?
Pleoptics is the technique of using light to stimulate or dazzle parts of the retina and give it a proper foveal direction, and is the most sophisticated method available.
The visual acuity of the eye is highest in the part of the retina termed the fovea. Hence in an effort to improve the vision, the eye must be trained to look at objects using the fovea or, to put it simply, in a proper foveal direction. Undermentioned are optical methods of achieving this important function.
There are many techniques. The one described is the most popular based on the work of Professor Bangerter. In this method, there are three stages of exercises to achieve a good foveal direction.
Stage I is stimulating the fovea by flashes of light so that the brain can appreciate which is the area that should be used. Thus the repeatedly flashed area is taught to point or project in the correct direction. The instrument which uses this combination of dazzling and stimulating is called a pleoptophore.
Stage II is developing proper forced fixation, so that the eye automatically sees any object only by the fovea. This is done using a polarised rotating filter which has the unique property of only stimulating the fovea and to a normal eye looks like the whirling propeller blades of an aeroplane or a fan. This unit is usually mounted on the previously described versatile synoptophore or on an instrument termed a centrophore.
Stage III is improving the visual acuity so that the patient sees more from the eye which has by now learnt to look and fuse at an object using his fovea. This is reinforced by also combining the hand with eye movement so that the ability settles down permanently.
A very intriguing but functional technique.
This section has been described simply so that the reader can appreciate that eye exercises are very useful and have curative properties, properly applied. But the techniques are sophisticated and need medical supervision. Considering the superb accuracy of the human eye which far transcends the most sophisticated electronic camera made, it is not surprising that the exercises need precise instrumentation to be really effective clinically.