Eye accommodation – causes, types, treatment. Exercises for eye accommodation

In other words, accommodation is readjustment of the eye. Under this concept is the ability to clearly see objects that are both near and far. Accommodation is directly related to changing the shape of the lens. It is possible, among others due to contractions of the ciliary muscle. All accommodation disturbances affect our life and work. Accommodation is a process that enables you to see clearly even very distant objects. The process is very complex and requires many changes to the eye. Find out what accommodation is and what causes visual acuity problems.

What is eye accommodation?

Accommodation, or eye alignment, enables you to see clearly at any distance. This is possible due to the contractions of the ciliary muscle.

The lens of the eye is somewhat flexible. This makes it possible to change its shape. The lens may become more spherical as the ciliary rim tightens the lens capsule. The strength of this tension is controlled precisely by the ciliary muscle.

When our eye wants to see an object that is close, the lens thickens (the effect of its elasticity), and the circular fibers of the ciliary muscle and the muscles of the iris contract. If we want to look at distant objects, the reverse process takes place.

Accommodation – changes in the eye

During accommodation, a number of changes occur in our eye, which allow us to see sharply both up close and from a distance. These include:

1. narrowing of the pupil of the eye,
2. shifting the pupillary edge of the iris forward and the entire anterior surface of the lens forward,
3. ciliary muscle spasm,
4. the approach of the ciliary muscle to the lens,
5. loosening of the rim fiber,
6. emphasizing the front surface of the lens,
7. highlighting the back surface of the lens,
8. drop of the lens down,
9. forward displacement of the choroid.

Eye accommodation – disturbing factors

Unfortunately, the older we get, the less flexible our lens becomes. Thus, her ability to accommodate is also diminished. Activities that require sharp vision at a short distance become problematic. Accommodation problems begin to develop at the age of 40 and last until the age of 60-70. Then the ability to accommodate completely disappears in the human eye.

The accommodation is also influenced by various factors that disturb this process. These include, among others:

1. vision related diseases,
2. various systemic diseases,
3. various pharmacological agents, e.g. nervous system stimulants, allergy medications,
4. alcohol, marijuana, narcotic substances and drugs,
5. in the case of children, accommodation is disturbed by various diseases, e.g. mumps and even the flu,
6. arsenic poisoning,
7. encephalitis,
8. multiple sclerosis,
9. diabetes,
10. anemia,
11. Parkinson’s disease,
12. head injuries,
13. encephalitis.

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Eye accommodation – types of dysfunctions

Accommodation problems are divided into two groups:

1. excessive accommodation (aka accommodation spasm),
2. insufficient accommodationwhich is divided into five types: impaired accommodation, insufficient accommodation, accommodative fatigue, accommodative heaviness, accommodation paralysis.

Eye accommodation – condition assessment

Various problems with accommodation have an impact on our quality of life and efficiency at work. Ideally, at the time of each eye examination with your ophthalmologist, you should also measure your eye’s accommodation capacity. This examination should be performed regardless of age.

In order to properly assess the state of accommodation, it is also worth measuring:

1. accommodation amplitudes,
2. accommodation efficiency,
3. accommodation responses,
4. stability of accommodation,
5. AC / A ratio.

Eye accommodation – range and amplitude

The work of accommodation can be assessed on the basis of the scope of the accommodation and the amplitude of the accommodation. These two parameters also make it possible to detect accommodation disturbances. The term eye accommodation range should be understood as the value of the distance between the near point and the distance point:

1. the visual near point is the closest point that the eye can see acutely thanks to accommodation;
2. the visual distance point is the farthest point the eye can see with accommodation off.

In contrast, the amplitude of accommodation represents the greatest possible change in the accommodation of the lens. We distinguish it:

1. the near point, i.e. the closest point for which the eye, thanks to the accommodation, creates a sharp image;
2. the far point, which is the farthest point at which the eye can create an image on the retina.

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Eye accommodation – accommodative contraction

Disturbance of eye readjustment is a problem of people of all ages. Their frequent cause is an accommodative spasm, i.e. excessive accommodation, which means that the course of the accommodative reflex has been disturbed. In such a situation, the reaction to the stimulus is too strong. The ciliary muscle begins to contract excessively, and the constant, strong accommodative tension makes it difficult to relax. For this reason, we do not see clearly when looking into the distance.

An accommodative contraction is much more common in people with uncorrected hyperopia and in people who frequently observe objects closely, e.g. working at a computer. This problem can also be seen in an increasing number of children and adolescents.

The cause of accommodative spasm is also:

1. muscle paralysis;
2. neurological disorders;
3. some ophthalmic diseases such as iritis;
4. general diseases;
5. certain medications.

Eye accommodation – insufficient accommodation

Insufficient eye accommodation is another problem that causes visual disturbances. In the case of weakened accommodation, the following should be distinguished:

1. accommodation failure – the term denotes problems in quickly sharpening the image when changing from looking into the distance to objects located close – this happens regardless of the correct amplitude;
2. insufficient accommodation, which is a decrease in the efficiency and amplitude of accommodation;
3. tiredness of accommodation, which means that the eyes tire quickly and visual acuity drops during long working hours when looking at close-ups;
4. heaviness of accommodationwhich represents a delayed accommodative response;
5. accommodation paralysis, which means no accommodative response.

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Eye accommodation – treatment of disorders

If the accommodation disorder is due to presbyopia, there are several ways to treat it:

1. wearing glasses – it is one of the simpler methods of treating eye accommodation disorders. This method is used in people who have previously been diagnosed with a vision defect. She can then wear progressive glasses. These glasses make it possible to see distant objects thanks to the upper part of the lens, to see distant objects indirectly thanks to the lower part of the lens and to see objects at a distance of less than half a meter, and to read thanks to the lower part of the glasses. Progressive glasses can also be used to correct vision defects. They are very convenient and do not require multiple pairs of glasses for different activities;
2. wearing contact lenses – for example, multifocal lenses are very effective, as they allow you to see both near and far;
3. operation – the procedure consists in getting rid of the eye lens and replacing it with a multifocal lens;
4. laser vision correction – it is a procedure that is gaining more and more popularity. It consists in modeling the cornea, thanks to which the patient sees sharply both up close and from a distance. Importantly, there is no need to wear glasses.

When accommodation spasm is the problem, it is necessary to remove the cause of the over-accommodation. Treatment of accommodation spasm therefore also involves changing habits. This means more breaks, less time in front of your computer, and more outdoor activity. Treatment with the use of Hart’s charts and pincers, i.e. two pairs of negative and positive spherical lenses, which help to relax and tighten the ciliary muscle, can also be a support for treatment.

Eye accommodation – exercises

Eye accommodation disturbances can be avoided. Prevention of accommodation disorders includes, first of all, regular eye exercises. While some say that eye accommodation exercises are impossible because the process is automatic, many experts say that strengthening the ciliary muscle is important.

The exercises are quite simple:

1. Exercise 1: one should cover one and the other one should look at an object in the distance and observe it for approx. 20 seconds to make the image as sharp as possible. Then we look with the same eye at an object standing very close to us, and again keep our eyesight on it for 20 seconds. We do the exercise for 3 minutes in one eye;
2. exercise 2: start reading a book. As you read, slowly move the book away from you until the text slowly becomes blurry. Then the eyesight needs more and more time to be able to read the text. We move the book away from us to the length of straight arms. Then we focus for a moment on the book itself, which will help to loosen the accommodation, and then we start reading the book again, bringing it closer at the same time. We perform the exercise for 3 minutes for each eye.