Vision loss: causes and prevention

It is one of the top ten disabilities in adults and one of the most common disabilities in children. Currently, three out of 4 adults report having a vision disorder, which can have different natures and origins.

Refractive anomalies

Thus, there are the refractive abnormalities where most of the problems are due to bad curvature of the cornea or an abnormality in the axial length of the eye. These include myopia (decreased visual acuity from afar), hyperopia (visual acuity is reduced at any distance but even more in near vision), astigmatism (associated with myopia and/or farsightedness, astigmatism is due to an anomaly in the shape of the cornea) and presbyopia (characterized by a decline in near visual acuity due to age).

In these cases, a simple correction with corrective glasses or contact lenses may be sufficient, but in other cases, treatment with corticosteroids, for Horton’s disease for example, may be necessary. Horton’s disease is one of the autoimmune diseases, the causes of which are still unknown and in the most serious cases it can lead to sudden, partial or total loss of vision in one eye.

Age

Certain other pathologies require an operation, such as cataracts, which correspond to an opacification of the main lens of the eye, the lens, which is accompanied by a feeling of veil in front of the eyes. It is most often progressive and age-related. Cataract is the first cause of blindness in the world, in France it affects 20% of the population from the age of 65 and more than 60% from the age of 85.

Another condition that particularly affects the elderly is macular degeneration (AMD). It is an ophthalmological condition that results in a progressive loss of central vision. It is the first cause of visual impairment among people over 50 in France.

After age-related macular degeneration, glaucoma is the second cause of blindness in developed countries and affects around 1% of the population aged over 40. It is a chronic disease caused by the progressive destruction of the fibers of the optic nerve under the influence of various factors, the most common of which is the abnormal elevation of intraocular pressure.

Virus

Among other eye disorders, keratitis can be caused by a virus of the herpes group, an adenovirus, certain amoebae (transmitted by dirty contact lenses), certain radiation (UVB), or various chemicals brought into contact with the eye. ‘eye. This can lead to visual sequelae like distorted vision.

We also note uveitis, which is more often caused by an infection (herpes, chickenpox and shingles). The anterior form of the disease can be caused by different chronic diseases: sarcoidosis, ankylosing spondylitis, Crohn’s disease, etc. Severe uveitis can cause irreversible loss of vision or cause glaucoma, optic nerve or retinal problems, or cataracts. The main symptom of uveitis is red eye.

Migraine with aura

Ophthalmic migraine (or migraine “with aura” which constitutes 20% of migraines) is manifested by the appearance of visual, sensory or phasic (language) disorders before the onset of the headache. These may be bright white spots, tingling or speech disturbances.

Diplopia is another visual disorder with the perception of two images of a single object. Diplopia can be mono- or binocular. Monocular diplopia is only present when only one eye is open. Binocular diplopia disappears when one of the two eyes is closed, according to the MSD Manual. There is also a risk of seeing blurred when there is a foreign body in the eye: the consequence is partial or total loss of vision in the affected eye.