At the behest of the optics, the lens it's a object normally made of glass, transparent, whose faces are not flat but are curved and as a consequence of the phenomenon of refraction, the light rays that hit one of the faces will be deflected and appear on the other. It is normally used in various elements used in optics.
Meanwhile, the lens can be convergent or convex, that is, it has a greater thickness in the center than at the ends, or failing that, be divergent or concave, having greater thickness at the ends than in the central part.
Lenses are generally used to correct vision difficulties in human beings and are also present in instruments such as: magnifying glasses, cameras, image projectors, telescopes and microscopes, used the latter two in scientific research contexts.
It should be noted that the first telescope to perform astronomical assessments was created by Galileo Galilei, using both a convergent or positive lens and a divergent or negative lens.
For their part, the lenses used to correct vision problems, also known as glasses, spectacles, and bifocalsThey consist of two crystals that are held through a frame. These lenses have different powers and are used especially in cases of presbyopia, myopia or hyperopia.
Other types of lens are: contact lens (They are lenses that are concave on one side and convex on the other, which are placed on the eye, more precisely on the cornea, for cosmetic purposes, to modify the original color of the eyes, or to reduce vision problems) and intraocular lens (It is a type of lens that can be made of silicone or acrylic and that is implanted by surgical means in the patient's eye with the intention of improving a condition in the lens or in the shape of the cornea).
On the other hand, those lenses that are used with the intention of protecting the sight from the sun's rays are also called lenses but of the sun.
The aforementioned terms of glasses and spectacles are the ones that are mostly used as synonyms for this term.
