What are Prism Lenses?
Prism eyeglass lenses are special lenses built into your prescription lenses to help with eye conditions such as double vision (diplopia) and binocular vision issues. Prism glasses help with double vision and binocular vision issues by altering the direction of light so it focuses towards the retina in order to see one image. Prism lenses are typically made from plastic.
How Do Prism Lenses Work in Glasses?
Prisms work in glasses by bending the light correctly before it passes through the eye. Prism lenses are built with prisms infused into the lenses which enables the redirection of light so it reaches the retina at the correct focal point aligning the two separate images. Your prescription will decide if a vertical or horizontal prism is required and can extend up to 4.0 and 6.0 diopters. A prism is defined as a transparent or glass material that bends or refracts the light that passes through it as a result of the plane faces and angles of the prism shape.
What are Prism Glasses Used For?
Prism glasses are used for the correction of eye conditions such as double vision and binocular vision issues. Prism glasses are prescribed to patients with either double vision or binocular vision issues, which can help correct how the light that enters the eye is refracted. This will enable patients to see one clear image instead of two images of the same object.
Do You Need a Prescription for Prism Eyeglasses?
Yes, you do need a prescription for prism eyeglasses. You need to obtain a prescription by booking an eye test with an optometrist, which can help determine how severe your double vision or binocular vision issues are. According to the American Academy of Ophthalmology, there are a number of tests to evaluate whether prism should be added to your prescription glasses. The different tests for prism lenses include the Krimsky test, cover/uncover test, prism cover test, prism and alternate cover test, Howell test and the maddox rod test.
How Do You Get a Prescription for Prism Eyeglasses?
To get a prescription for prism lenses, you can book an appointment with an optometrist so they can examine your eyes and assess whether you require prism in your prescription. The optometrist will run different tests that help them to evaluate the health of different regions in the eye. You will know if you require a prism if there is a number in the prism column on your prescription and if you are experiencing double vision. If you already use prescription glasses, you can book an eye test to see if your prescription needs updating.
How are Prism Lenses Added to a Prescription Glasses?
A prism is added to a prescription glasses’ lens by making one of the lenses thicker than the other lens, which causes incoming light to bend in a certain way. Prism comes in different levels of strength depending on the extent of your condition, which can start from 0.5PD, 1.0PD, 1.5PD, 2.0PD and so on.
What are the Side Effects of Prism Glasses?
The side effects of prism glasses may include a headache, nausea and eye pain. Let your optometrist know if you are experiencing any of these side effects of wearing prism glasses right away so they can either adjust the fit of the frame or update your prescription. The possible side effects of prism glasses are listed below.
- Headache:: A headache is characterised by pain felt in and around the head and can occur as a side effect of prism glasses if you are new to wearing new prism glasses.
- Nausea: Nausea is defined as discomfort in the stomach and the sensation of wanting to vomit and may be brought on by prism glasses during the initial stage of use. However, if this symptom persists, you should see your optometrist.
- Eye Pain: Eye pain from prism glasses may occur if the glasses are not properly fitted or the prescription needs updating.
What are the Eye Conditions That Prism Glasses Correct?
The eye conditions that prism glasses correct are double vision (diplopia) and binocular vision issues. Double vision also known as diplopia is an eye condition that causes a person to either see two distinct images or two overlapping images of the same object. There are two types of diplopia, binocular diplopia and monocular diplopia. Binocular diplopia only occurs when both eyes are open and monocular diplopia occurs even when one eye is shut. Causes of double vision (diplopia) include cataracts and astigmatism, nerve-related problems that affect the eye muscles and brain-related conditions such as a stroke and an aneurysm. Binocular vision issues are when the eyes fail to work together properly or are misaligned as a result of an abnormal visual system, a stroke, brain injury or other neurological disorder. Symptoms of binocular vision issues can include eye pain, eye strain, blurry vision, light sensitivity, double vision and poor night vision. Other than prism glasses, vision therapy can also be used to treat binocular vision issues according to the Cleveland Clinic.
Do Prism Glasses Correct Binocular Vision Dysfunction (BVD)?
Yes, prism glasses can correct binocular vision dysfunction. Prism glasses aid binocular vision dysfunction by changing the direction of incoming light so it reaches the correct focal point on the retina. Binocular vision dysfunction (BVD) causes the eyes to misalign making it difficult for the eyes to send one distinctive image to the brain.
How are Prism Glasses and Reading Glasses Related?
Prism glasses and reading glasses are not necessarily related, however, prism lenses can be prescribed to your reading glasses to correct your double vision or binocular vision issues. Reading glasses are defined as prescribed glasses designed to view objects and text at a near distance.
Can You Add Prism Lenses to Reading Glasses?
Yes you can add prism lenses to reading glasses. Adding a prism to reading glasses will require an eye test with an optometrist first to determine the strength of the prism necessary for your condition. The optometrist will run certain tests based on the symptoms you present and what you may be experiencing with your vision. If you do need a prism added to your lenses, your prescription will have a number in the prism column. Prisms are added to reading glasses during the lens production process, however, if you only require a temporary prism, a stick-on prism may be placed on your glasses after they are made.
How to Choose the Right Prism Glasses For Your Eye Condition?
To choose the right prism glasses for your eye condition, you will need to book in to see an optometrist. The optometrist will help you choose the right glasses for your eye condition as they will have the necessary information to help narrow down the most suitable options, including adding prism lenses. According to the American Academy of Ophthalmology, prism glasses feature a thicker and more noticeable lens on one side, therefore, you may want to choose a thicker frame to help hide or reduce the appearance of the thicker prism lens.
