As we get older, we may find blurring in dim light and even start to stretch our arms to read. You should be vigilant, and you may have presbyopia. Don't worry. Presbyopia is just a normal physiological phenomenon. All we need to do is go to the hospital for an eye exam. Do you know how to read prescriptions? It is essential to learn to read prescriptions when you do not want to spend much money on an expensive pair of prescription glasses. After learning, you can buy reading glasses according to it.
The picture below is an ordinary prescription. You may not be able to read the meaning of the words in the table.
Sph is short for sphere, and you may also see S or DS, which stands for strength. If it is a positive sign, it means farsightedness. Conversely, if it is a negative sign, it means myopia. Next, Cyl is short for Cylinder, and also write C or DC. If there is a number, it means you also suffer astigmatism. Axis or AXI or X refers to the axial position of astigmatism. Astigmatism is a type of refractive error. The value of Axis is usually between 0 and 180. Prism is used to correct strabismus problems, and only a few percent will include prism. The last one is Add, which refers to the additional lens strength you need to read. Add in the main parameter for making progressive lenses. If you only need a pair of reading glasses, it is unnecessary.
You may also not know what PD means. PD refers to pupil distance, which is the distance between pupils. In the above picture, PD refers to the monocular interpupillary distance. It means the distance from the center of the pupil to the center of the bridge of the nose.
Now that we can read prescriptions choosing the proper reading glasses is simple. There are different power glasses from +0.25 to +6.00 on Eyekeeper, and you can select the most suitable ones for yourself. If you need separate lens power for two eyes, Eyekeeper also can help you solve this problem! There are different strengths of reading glasses for each eye on Eyekeeper. You can click here to learn more.