(Newswire.net — May 3, 2020) — There are countless reasons why some people might need glasses. While some people wear them as a fashion accessory, the vast majority of people wear them to correct some sort of vision issue. The most common problems that cause people to have to wear glasses are myopia (which is nearsightedness), hyperopia (which is farsightedness), astigmatism (which causes the proportions of the image the distort), and presbyopia (which is age-related vision loss, causing people to wear reading glasses). Now, people can order glasses online. This is a nice change of pace; however, people also need to know which type of glasses they need. In order to figure this out, there are a few parameters that people need to know.
First, the most important parameters are called OD and OS. OD shows the prescription information for the right eye. OS shows the prescription information for the left eye. If there is a minus sign in front of these parameters, it usually means the person is nearsighted. If there is a plus sign in front of these parameters, it usually means the person is farsighted. Usually, these two numbers are close; however, they aren’t typically the same in each eye. These numbers need to be correct in order for someone’s vision to clear up.
The next sign is the CYL, which stands for the cylinder. This is usually only an issue for those with astigmatism. This specifies the axis of the lens which is needed to get the eye to focus clearly at certain angles.
Those who need reading glasses may see something called an add. The add is a specified correction that is meant for those who need glasses for reading. This number is important for reading, bifocal, and varifocal lens glasses.
Finally, some people might see something called a prism. This is used to help someone with a lazy eye to correct their vision. This can be included with a prescription that is needed to correct some special ocular issues.
These are some of the most important metrics that people need to know in order to find the right glasses for them. Over time, people’s numbers may change, so it is still important to see an eye doctor regularly. Knowing these numbers will help people find the right glasses for them. Then, they can head to the internet and find a convenient pair of glasses that will fix their vision issues or even blue blocking reading glasses.