Non spherical glasses, as the name goes, are not round shaped but usually in a rectangle or square form. These glasses are usually prescribed for you when you see the doctor according to the lens that you need. When it comes to the interpretation of the lens that you need the doctor will have to check your eyes. There are different terms used to write down an eye prescription. Oculus Sinister ( OS) for instance refers to anything that has to do with the left eye. Oculus Dextrus (OD) on the other hand is a term for anything that has to do with the right eye. The further away from the zero marks that you are, the worse your eyesight and the stronger prescription that you need.
The likes of the nonspherical glasses can be for fashion as well as for medicinal purposes. The dioptre (the unit used to measure the correction or focusing the power of the lens the eye requires) is used in interpreting the prescriptions of the eye. Therefore, a reading of -1.00, for example, means you have one dioptre of near-sightedness while a +5.00 shows that you have 5 dioptres of farsightedness. Luckily, when you detect any eye defect quickly, it can be solved for you through eye checks.
If you have astigmatism and you are going for a frame for your glasses, you can have the option to chose from these nonspherical glasses shape. Astigmatism is when there is an error in the shape of your cornea. It means the surface of the eye has an irregular curve. It affects the way light passes through the eye and how thing appears. You will, therefore, have blurry or fuzzy images or a distorted vision altogether. When light rays enter the eyes, the images are distorted. The causes of astigmatism are not really known but sometimes doctors suspect genetics which may be present at birth or when you grow.
The eye conditions that lead you to look for glasses differ. For some people, they need it because of dust. Others just want to look good and dignified. Having on spectacles does give you a prim and proper look. The older people use it for corrective purposes for their eyes. Its sometimes among the youth that the fashion sense of the glasses is explored. Nonspherical glasses have their own beauty and can be a good choice for anyone who needs one for their eyewear.