There are a wide variety of vision problems today. The most common affect our ability to see our surroundings clearly and can be corrected with ophthalmic lenses . Here is a short list to help you understand better.
The eye is a machine with incredible capabilities. However, sometimes it can fail. Its optical functioning is complex, so even minor defects can cause vision to be blurred or imperfect. In Mexico , almost 3 out of every 4 adults have vision problems. Fortunately, the most common things can be easily corrected with ophthalmic lenses.
Myopia
Ideally, the eye should allow us to see clearly far away without any focusing effort. In other words, the image of a distant object should be projected onto the retina without any effort. But with myopia , the eye is too long or too “powerful,” and the image of the object is formed before reaching the retina. This is the reason why myopes perceive distant objects as blurry.
To compensate for this visual defect, it is necessary to use glasses or lenses that compensate for this visual defect, either divergent or negative glasses that repel the image of the object on the retina.
Farsightedness
Hyperopia is the opposite of myopia: the eye is not “powerful” enough or too short, and the image of the object is formed behind the retina. As with myopia, distant objects should appear blurry. But only in theory, because in the case of farsightedness, the eye can usually make an effort to focus and replace the image of the object on the retina thanks to accommodation. Therefore, in practice, the farsighted person will see clearly far away, but the effort made in distance vision will be added to the effort to focus in near vision. Likewise, hyperopic people suffer more from near vision alterations: visual fatigue, loss of concentration, headache, blurred vision ...
Correction with glasses or converging monofocal lenses relieves near vision disturbances in the same way.
Astigmatism
Astigmatism is a more complex refractive error: it is due to inequalities in the curvature of the different parts of the eye (cornea, lens, retina, etc.). In other words, your eye distorts objects: the image of a circle, for example, will have an ovoid shape in the back of your eye, and your vision will be blurred and distorted at all distances. This refractive disorder is often combined with myopia or hyperopia.
To correct it, so-called cylindrical glasses are used, which make it possible to compensate for irregularities in curvature.
PRESBYTIA
Presbyopia is the result of natural aging of the eye . In fact, with age, the lens becomes increasingly rigid. And if it doesn't cause an extra problem seeing from a distance, it adds extra difficulty focusing on close objects. There are different solutions to overcome this disorder: the use of glasses (lenses) for reading or any activity at short distances, or the use of progressive or multifocal optical lenses , which correct vision both near and far.
