Myopia: How to identify the symptoms and correct blurred vision

Myopia is a defect in the refraction of light entering the eye. The light is not focused directly on the retina but in front of it, which results in seeing distant objects blurry, while objects that are close up are not. Myopia is one of the most common vision problems worldwide and affects both sexes and all ages. It can be corrected with glasses, contact lenses and refractive surgery.

Causes of myopia Hereditary or defects in the curvature of the cornea or lens

Children of parents with myopia are considered to be more likely to develop this vision defect. In addition, it is noted that a defect in the curvature of the cornea or the lens, the elements of the eye responsible for refracting (deviating) light rays on the retina and which must have a perfectly smooth curvature, do not have a smooth and uniform curvature in those affected by myopia. Due to not having the correct curvature, when the eyeball is longer than normal or the curve of the cornea is too pronounced, the light is focused in front of the retina, producing blurred images of distant objects.

In recent decades, the appearance of myopia has been associated with spending little time outdoors, with the possibility of looking into the distance, and work and studies with a limited field of vision (working with a computer, continuous use of screens, reading for hours, holding reading material very close to the eyes, etc.).

Myopia can have several classifications but is usually differentiated into:

- Simple myopia: When the prescription does not exceed 6 diopters and develops until the age of 24.

- High, progressive or pathological myopia: When the prescription exceeds 6 diopters and may worsen with age. It may present complications such as retinal detachment, myopic maculopathy or glaucoma.

Symptoms of myopia Blurred vision and others

The need to squint to try to focus better for distance vision is often the first sign that it is necessary to visit the ophthalmologist. Other symptoms include:

- Blurred vision of distant objects.

- Headaches due to eye fatigue.

- Poor night vision.

- Need to sit closer to the TV.

- Blinking excessively.

- Rubbing your eyes frequently.

Diagnosis of myopia Ophthalmological examination

An eye examination with tests of distance and near vision acuity should be carried out regularly. Every two years for those who have not had visual acuity problems since they started school, and at least every year for those who already have vision problems.

To confirm the diagnosis of myopia, the ophthalmologist will have the patient read:

- The Jaeger optometric table (the table for short distance reading).

- The Snellen eye chart (the chart for distant reading).

He or she will also measure eye pressure, examine the structure of the front of the eyes and the muscles that move the eye, perform a retinal exam and a refraction exam to determine diopters. He or she may also perform a test to rule out or confirm color blindness.

It is a reason for an emergency visit if you notice small particles that seem to float in your visual field, flashes of light in one or both eyes, or a curtain-like shadow in your visual field.

Treatment and medication for myopia Glasses, contact lenses

Prescribing glasses with divergent lenses or contact lenses with a prescription that matches the diopters measured by the specialist is the solution that helps the patient achieve a clearer image of distance vision by changing the focus of the light image directly on the retina.

If myopia has stabilised, the specialist may consider performing refractory surgery such as:

- Laser-assisted in situ keratomileusis (LASIK), in which inner layers of the cornea are removed to flatten it.

- Laser-assisted subepithelial keratectomy (LASEK) in which the outer layers of the cornea are reshaped to flatten the curvature.

- Photorefractive keratectomy (PRK) removes the epithelium, the outer protective layer of the cornea, which then grows back naturally and the cornea is reshaped with the laser.

It is important to know the side effects of the different surgical techniques and the postoperative measures, which must be followed very strictly, since they are non-reversible methods.

Prevention of myopia Spending time outdoors

Avoiding spending many hours reading or using screens (on the computer, watching TV, playing games on screens or on the smartphone) and trying to spend time outdoors looking into the distance helps combat eye fatigue. A healthy, balanced diet rich in:

- Vitamin A and rhodopsin, a pigment that helps us see in low-light situations. Carrots are sources of vitamin A and rhodopsin

- Vitamin E such as almonds, peanuts, pine nuts, sunflower seeds and dried apricots.

- Lutein, a nutrient found in cabbage, spinach and turnip greens.