Main visual conditions in adolescence

Astigmatism is a refractive error that causes blurred and distorted vision, both near and far vision, and that manifests itself when images are focused on several points on the retina. In contrast, in emmetropic (non-prescription) eyes, images focus on a single point on the retina.

People who suffer from astigmatism are characterized by alterations in their corneal curvature, that is, their cornea has an irregular curvature, instead of being symmetrical.

This visual anomaly does not always occur in isolation, as it is often associated with myopia or hyperopia.

Like nearsightedness and farsightedness, astigmatism can be genetically determined. It may also occur after trauma, injury, or illness, or as a consequence of eye surgery.

Astigmatism is the third most common visual problem among Spaniards (behind myopia and presbyopia or eyestrain), since more than a quarter of the population suffers from it.

The main symptom of astigmatism is blurred and distorted vision of near and distant objects, as well as difficulty perceiving small details at all distances.

When astigmatism is associated with hyperopia, it is common for the patient to present symptoms such as visual fatigue, redness, itching and stinging of the eyes, dizziness or occasional headache, due to the overexertion made by the eye to focus on images.

The symptoms that the patient may perceive are different depending on their age, type of astigmatism or prescription. However, in mild cases it is possible to miss any signs of astigmatism.

Conjunctivitis is inflammation of the conjunctiva, a clear membrane that lines the sclera (white part of the eye) and contains small blood vessels. When these vessels become inflamed, the eye becomes red. It usually evolves favorably, unless it is not treated appropriately.

The cause of conjunctivitis can be a bacterial or viral infection, an allergic reaction due to exposure to an agent (allergens) that induces hypersensitivity in some people or, also, an irritation of the edge of the eyelid (blepharitis) as a result of the use of cosmetics or contact with irritating substances in the environment. Each of these causes gives rise to different types of conjunctivitis: infectious conjunctivitis, allergic conjunctivitis, irritative conjunctivitis.

The symptoms of conjunctivitis are very visible and characteristic, such as eye redness, itching (predominant in allergic conjunctivitis), tearing, secretions and stuck eyelids (especially in bacterial conjunctivitis). To a lesser extent, when conjunctivitis occurs with complications, it can produce a foreign body sensation inside the eye, greater sensitivity to light and significant inflammation of the eyelids.

Farsightedness is a refractive error that causes blurred and uncomfortable vision of nearby objects (and sometimes also distant objects). Unlike myopia, the images are focused behind the retina and not directly on it.

People who suffer from hyperopia are characterised by alterations in the different structures of the eye such as its corneal curvature, the optical power of its lens (low power) or the size of its eyeball (shorter than normal length).

Like myopia, farsightedness has an important hereditary component.

The main symptom of farsightedness is poor near vision. If the hyperopia is low, the patient will see well at a distance, although their effort to focus or accommodate will be greater. This can lead to other symptoms such as headache and eye strain.

In many cases, its effects are not noticed until, from the age of 40, the ability to accommodate is reduced.

Young people with hyperopia and low graduation do not usually manifest visual acuity problems since they compensate for it through the effort of accommodation.

Myopia is a refractive error that manifests itself when distant objects are projected at a point in front of the retina, instead of on it. As a result, a distorted perception of the image occurs and, therefore, vision is blurred and poorly defined.

People who suffer from myopia are characterised by alterations in the different structures of the eye such as its corneal curvature, the optical power of its lens (excessive power) or the size of its eyeball (excessive length).

Myopia is the most common visual defect among people under the age of 45 and can be associated with other refractive errors, such as astigmatism (myopic astigmatism) and presbyopia or eyestrain.

The main symptom of the patient with myopia is that they have poor distance vision and yet optimal near vision. Other symptoms you may suffer from are eye strain, headache, difficulty concentrating, permanent dry/itchy eyes, etc.

Myopia can progress during this stage of intense body development. In general, myopia tends to stabilize after the age of 20, although it will depend on each individual case.

Myopia progression in adolescence

Myopia increasingly affects young people, according to the report “The prevalence of myopia among young people in Spain, 2018” conducted by the Vision and Life Association. In fact, at present, 6 out of 10 suffer from this refractive defect. This means that more than half of young people of school age (mainly women) have difficulties with their distance vision. For its part, the World Health Organization (WHO) has described this visual disorder as a pandemic that will increasingly affect this age group.

This report reveals that young people born between 2000 and 2005, who belong to the so-called digital natives generation, have half a diopter of myopia more than young people of the previous generation at the same age. One of the main causes pointed out by experts is the exposure to electronic devices such as cell phones, computers, tablets, consoles, etc. One of the consequences of this intensive use is sedentary lifestyles, since the time young people spend in natural light is significantly reduced.

Technological changes in recent years and the social behaviors that go with them seem to have influenced this high rate of myopia among young people. The problem arises because myopia is a pathology that can be associated with other more serious visual disorders, such as retinal detachment or glaucoma, which can develop in adulthood.

This ocular pathology, also known as high myopia or pathological myopia, differs from normal myopia in that patients suffering from it have more than six diopters, as well as a greater propensity to present ocular alterations.

Magna myopia is due to an excessive elongation of the eyeball that is usually associated with a thinning of the retina. This exaggerated growth of the eye can lead to early onset of posterior vitreous detachment and is an important risk factor for retinal detachment (40% of cases occur in myopic patients). Likewise, this group of patients has a greater predisposition than the general population to develop cataracts and glaucoma more frequently.

Patients with magna myopia are usually nearsighted since childhood. This type of myopia can progress to more than six diopters, usually stabilizing by the end of adolescence, or it can continue to progress with age. When this situation occurs, it is called degenerative myopia and should be closely monitored by an ophthalmologist to avoid major complications.

The patient with this refractive defect presents blurred distance vision and lack of visual acuity, as well as optimal near vision, unless there is some type of macular complication. It is also common to perceive flashes of light and small spots on the retina (floaters or myodesopsia).