Lenses are a special kind of tool that improve our vision by focusing and bending the light. They bring also an important factor to how we perceive the world around us. Lenses are available in different types but some of the most prominent ones are spherical lenses and cylindrical lenses. These lenses correct vision problems that a lot of people have, but they do so in slightly different ways.
A lens is generally spherical (curved from all directions around like a ball). They are very handy and are used to correct most of the vision problems such as nearsightedness, farsightedness, and astigmatism, etc. Spherical lenses bend light in a way that will allow the light passing through them to focus properly on the retina, a part of the eye. The retina matters because it transmits signals to our brain to construct the images we observe. When the light does not meet correctly, we struggle to see the items obviously.
Cylindrical lenses are slightly different. They only bend in one direction, as would a cylinder. These lenses are designed specifically to correct a condition known as astigmatism, which can cause images to become blurry and unclear. Astigmatism occurs when the cornea, the clear outer part of our eye, is shaped unevenly. This makes light bend nonuniformly, and results in distorted images. Cylindrical lenses correct for this because they focus light more in one direction than the other, bringing images into greater clarity and focus.
There are primarily two spherical lens types, namely concave lens & convex lens. Concave lenses refers to a lens that is thinner in the middle than at the edges. They refract light outward, which can correct some vision problems. Conversely, convex lenses are thicker in the center than at the edges. These lenses enable to bend the light inward and thus able to focus it better. With a combination of both concave and convex lenses, people are able to see much clearer.
As we said before, cylindrical lenses are used to fix astigmatism. With astigmatism the cornea is not shaped completely round. This irregular shape refracts light differently, resulting in blurriness. Now this is where cylindrical lenses come in. They curve from top to bottom, bending light more in that direction. This allows the light to properly focus on the retina, significantly enhancing the persons vision.
An eye exam performed by an eye doctor will help determine the exact lenses someone needs. In this exam, the doctor will assess the curving of the cornea, see if the patient is nearsighted or farsighted, and measure the amount of astigmatism. After all the tests, the doctor will prescribe specific lenses for correcting the patient’s vision problem.
In certain instances, individuals with a high degree of astigmatism must wear a combined spherical and cylindrical lens. These specific lenses are referred to as toric lenses. They’re made to help with nearsightedness or farsightedness — along with correcting all that blurriness caused by astigmatism. Toric lenses are not just curved in one direction like a pair of cylindrical lenses; they have a little bit of a curve in the opposite direction as well like a spherical lens. This reshapes the frim portion of the clear covering in front of the eye, the cornea, an for admitting light forms suitable lines so that the eyes can spot a perfect see.
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