Eyesight Essential: Understanding Prescription Eyeglasses
Either you or someone you know wears prescription eyeglasses, which correct astigmatism, farsightedness, nearsightedness and age-related farsightedness – which are called refractive errors.
But have you ever wondered how eyeglass prescriptions work? Have a look at the information below to learn why prescription lenses provide clear and comfortable vision.
At Professional VisionCare in Lewis Center, we offer a wide range of prescription glasses in a variety of styles, colors, and materials.
What Is An Optical Prescription?
An optical prescription is a document written by an eye doctor. It details the strength and type of corrective lenses that an individual needs to see clearly.
Information like whether the patient has astigmatism, nearsightedness (myopia), farsightedness (hyperopia) or presbyopia can be seen from the powers and information included. Then an optical laboratory uses the information to create eyeglasses or contact lenses that will help the individual see clearer in their daily life.
Types of Vision Issues Corrected By Prescription Eyeglasses
Prescription eyeglasses correct a variety of vision problems, including:
- Nearsightedness - Also known as myopia, causes the eyes to struggle with seeing distant objects. This happens when the eyeball becomes too long or the cornea becomes too curved. In myopia the light entering the eye is focused in front of the retina. Prescription eyeglasses for nearsightedness have lenses that are thicker in in the outermost portion of the lens, which allows them to refocus light directly onto the retina.
- Farsightedness - Also known as hyperopia, farsightedness is the opposite of nearsightedness. It’s caused by the eye being too short or the cornea being too flat, causing the light to be focused behind the retina. People who are farsighted find close-up objects blurry, such as reading or digital devices, but are able to clearly see distant objects. Prescription eyeglasses for farsightedness have lenses that are thicker at the center than at the edges, which allows them to focus light onto the retina to make seeing up close easier.
- Astigmatism - An eye condition where the cornea is irregularly shaped, leading to vision being distorted. Prescription eyeglasses for astigmatism have lenses that are curved in a variety of ways, depending on the specific type of astigmatism.
How Do Eye Doctors Create A Prescription?
Eye doctors create a prescription by performing a comprehensive eye exam. This allows them to measure the patient's visual acuity, refractive error, and ocular health.
Visual acuity is measured using a Snellen chart, which is a standard chart with letters, numbers, and symbols that a patient has to identify from a certain distance. Refractive errors are determined by using a phoropter or an autorefractor, which help the eye doctor decide if eyeglasses or contact lenses are needed and accurately determine the best optical prescription to provide clear and comfortable vision. Finally, the eye health is examined with a range of computerized devices check for signs of eye disease.
This information is used to create a prescription for eyeglasses or contact lenses that will enable the individual to see clearly and match their lifestyle.
Get Prescription Eyeglasses in Lewis Center
Prescription eyeglasses are essential for people who struggle to see clearly. If you’re experiencing blurry vision or it’s time for a new prescription, book a comprehensive eye exam with Professional VisionCare in Lewis Center today.