If you decide on making your first pair of glasses, or you just want to change your old ones, you will need an eyeglass prescription. The first step is visiting your ophthalmologist or optometrist. What many don’t know is the fact that the prescription is first written on a piece of paper, which contains your personal details required to make your own eyeglasses. Not many understand what this prescription means. In this piece, I will try to explain all you need to know about eyeglasses prescription.
Importance of frequent eyeglasses prescription
If you think that once you did your eyeglasses prescription, you can use it for life, it may surprise you this is not true. An ophthalmologist or eye doctors recommend carrying out a routine checkup for those using contact lenses and eyeglasses at least once every two years. Most eyeglasses prescription expires after two years.
Our eyes and bodies undergo constant change, which is why it is important to have a well-done eyeglasses prescription. Doing an eye check will ensure your eyeglasses or prescription lenses give you the optimal vision you require. Merely looking at the eye, it is difficult to detect any significant deterioration in your eyesight; however, an eye test can easily detect these changes. Additionally, if the vision of one of the eye changes, the other may compensate for it. This makes it hard for one to become aware of any deterioration. The hard truth is that leaving your eye unchecked could cause nausea, headaches, and eyestrain.
In the course of your eye examination, the ophthalmologist may check the overall health condition of your eye. Regular checkup will help your doctor detect many eye diseases that may occur without prior signs. The doctor may also measure the intraocular pressure while testing for warning signs of glaucoma and signs of macular degeneration. If these are undetected, it could result in permanent loss of sight, which you won’t want considering the importance of vision. Nevertheless, with the advances in technology, doing your eye checkup shouldn’t be a challenge anymore.
Reading eyeglass prescription without an ophthalmologist
Have you gone to the ophthalmologist and done your eyeglass prescription only to be confused by the inscriptions on the paper. Well, you shouldn’t be because it is as simple as ABC if you follow the explanations below.
Looking at the eyeglasses prescription given to you by your doctor, you will notice certain numbers listed under the headings of OD and OS. These are Latin abbreviations that mean oculus dextrus (OD) for the right eye and oculus sinister (OS) for the left eye. Intermittently, another notation OU may be used; it means something that involves both eyes. Generally, the farther the number is from zero on the prescription, the worse your eyesight is and the more vision correction you will need.
When you see a “minus” (-) sign in front of the number, it signifies that you are nearsighted but a “plus” (+) sign signifies farsighted. These numbers are a representation of diopters. Diopter is the unit used in meaning the correction or focusing power of your lens required for your eye. It is mostly abbreviated D.
For instance, if your eyeglasses prescription reads a -1.00, it means you are one diopter of nearsightedness. However, if it reads -4.25, it means you have 4 and ¼ diopters of nearsightedness. This second reading is more nearsighted when compared to the first and will require a thicker or stronger lens. In the same vein, a +5 would be more when compared to +1.
People who have issues with astigmatism, they will have three different numbers in their prescription. The general writing is as follow:
S x C x Axis
The S refers to the “spherical” aspect of the eyeglass prescription. This is the degree of farsightedness or nearsightedness as explained earlier. The C refers to astigmatism or “cylinder”, and could be apositive or negative number. The more the number, the more astigmatism you have. A primary cause of astigmatism is cornea, which has the shape of a football. The Axis refers to anumber between 0 and 180 degrees. It shows the orientation of astigmatism.
How is Prescription eyeglasses made?
Eyeglasses are important for people having vision issues. Their invention dated back to centuries ago and has brought improvement in people’s vision. Wye glasses enable people to do what they couldn’t do before such as reading a book or driving a car. The human lens and eyeglassesutilize the same principle and work by supplementing the lens function.
The lens of the human eye is located between the cornea and the retina. The cornea is the front of the eye whereas the retina is the layer of cells at the back of your eye. The lens of the eye is convex in shape and works with the cornea to project and focus on images directly on the retina. In turn, the retina reacts to the image, which sends signals to the brain.
Making your prescription glasses is start by determining the prescription, or the strength of the correction needed. This takes place in the doctor’s office during your eye test. Immediately the prescription is gotten, the numerical value is sent to the laboratory to provide what is needed for the creation of the glasses. These numerical values and their meaning shouldn’t be a mystery to you because we have explained what they mean.
Your eyeglasses start as a blank lens in the laboratory. It is either made from a glass disc or a plastic, which are about four inches wide and ½ inches thick. This blank lens has a curved front surface with a flat back surface. The lab technician takes the black lens and puts it into a machine to grind it according to the required curve. The thickness of the lens is determined by the prescription of the curve in the prescription. The grinding process needs a painstaking accuracy to ensure that the made eyeglasses are according to the prescription by the doctor. These glasses are made without any scratches on them because it may affect their function.
After this, the lenses are edged to fit the frame chosen by the patient. At this point, the eyeglasses are coated or tinted by using a tinting solution. After this, a groove being cut is made into the lenses to ensure the glasses fit into the frame. Finally, the lenses are neatly inserted into the frame. The lenses are either treated or heated with chemicals. The chemical is important because it makes it flexible for easy insertion. Then a properly checkup is done to ensure there is no imperfection.
Summary
Getting your eyeglasses prescription done perfectly is crucial to your vision. Besides this, carrying out routine checkup is paramount if you value your eyes. Ensure you get your prescription from a certified doctor instead of buying “Not recommended” glasses for your eyes.