How to Tell (Quickly) if You Are Nearsighted
Table of Contents
How to Test Your Vision at Home
The American Academy of Ophthalmology provides a printable at-home eye test. You can print that test, hang it on the wall 10 feet from where you plan to stand, cover one eye, and attempt to read the figures on the chart. At some point, the items will grow hard to see. The line at which you can see the majority of figures correctly represents your visual acuity. There are small numbers off to the side of the chart corresponding to acuity, such as 20/20 or 20/40.
A score of 20/20 is considered optimal. This score indicates a person standing 20 feet from something can see an item as clearly as a healthy person standing 20 feet away. A score of 20/40 means a person would have to stand at 20 feet to see something that a healthy person can see 40 feet away. In rough terms, a bottom number higher than 20 indicates myopia.
To perform a true vision test at home, you should also consider what might be causing your myopia. The Prevent Blindness organization has a list of several questions that could indicate eye disease, and a “yes” answer to any question suggests that there is a problem in play. Questions include:
- Have you ever been diagnosed with or treated for glaucoma?
- Has your vision changed within the last year?
- Are you older than 65?
- Have you been through an eye injury or eye surgery?
Thinking through your medical record and your eye’s prior health could help to uncover clues that lead to your myopia symptoms.
If you are struggling with myopia, you probably already know it. You may squint to see things in the distance on a regular basis, and you may find that your squinting does not help. At advanced stages of myopia, you may not be able to see anything at all without the help of glasses or contact lenses.
It’s relatively easy to conduct an at-home vision test, and when you are done, you will have a good idea of how well you can see. But an examination with a doctor can tell you so much more about your eyes, and your doctor may be able to spot and treat conditions that contribute to low vision. That is hard or impossible to do at home.
A doctor can also give you a prescription for glasses or contact lenses to help you live with myopia. You will need that prescription to order glasses or contacts in most cases.
Your doctor may be interested in the results of your at-home test, however. And you can use those tests to help you understand when it’s time to see your doctor for an exam.
Understand What Myopia Is
Nearsightedness involves the ability to see things clearly only when they are relatively close to you. The technical term for this condition is myopia. It typically develops due to an elongated eyeball that focuses light on the middle, not the back, of the eye. The condition often appears in childhood, worsens through adolescence, and then stops changing (stabilizes) in early adulthood.
A prescription for myopia correction is measured in diopters, and the severity of the condition is also tracked in diopters. The American Optometric Association recognizes three basic myopia categories:
- Low myopia comes with a prescription smaller than 3 diopters.
- Medium myopia comes with a prescription between 3 and 6 diopters.
- High myopia comes with a prescription higher than 6 diopters.
According to the National Eye Institute, high myopia is associated with retinal detachment. The retina, located near the back of the eye, helps to interpret light that hits the eye. If the tissue detaches and is not reattached via surgery, it can lead to blindness. High myopia has also need associated with both glaucoma and cataract. Those conditions can also rob you of your sight.
Vision problems caused by medical emergencies like glaucoma are sudden and severe. They are very hard to ignore. But myopia can be subtle, and it’s not uncommon for people to have the condition and not know it. An at-home test could help you understand if you are dealing with undiagnosed myopia.
Why Should You Visit a Doctor?
Once you’ve performed an at-home vision test and you’ve made an honest assessment about your eye health history, you may feel as though you have all of the information you need to understand your myopia. Unfortunately, you can’t stop there. A doctor’s visit is always wise when you are not seeing as well as you should.
An eye care professional might also offer you a visual acuity test. According to the American Academy of Ophthalmology, that doctor can use sophisticated technology to understand the cause of your myopia. For example, your doctor might use a special form of light to examine the retina at the back of your eye. Your doctor can also use a tool called a phoropter to measure the amount of correction your eye needs. That tool will provide you with a prescription, which you will need in order to get glasses or contacts to help you see clearly with myopia.
Why You Need a Prescription
An at-home test can provide you with results pertaining to your visual acuity. When the test is complete, you may know that you can see at 20/40 in one eye and 20/60 in the other, for example. But this visual acuity result is not a prescription for glasses or contact lenses. That prescription only comes from a doctor.
At the end of a visual test with an eye care professional, you have a right to a printed copy of your prescription, according to the Federal Trade Commission. You are not required to pay extra for that prescription, and you are not required to use that prescription to buy glasses or contact lenses from your doctor. You can use that prescription anywhere you want to, including online.
An eyeglass prescription contains a variety of numbers, according to Medicine Net. In addition to numbers relating to your nearsightedness, your prescription may also include measurements of the degree of your astigmatism and the orientation of that astigmatism. Those numbers are crucial in creating the right lenses for you.
In an online shop, you can type in the measurements listed on your prescription, or you can scan your prescription and upload an image. Walk-in shops may work in much the same way. Some retailers require a prescription that is current and has not expired, but others have looser rules.
How to Use Your At-Home Vision Test
If you’ve discovered that you have myopia and you’d like to take steps to fix the issue, you will need a prescription. Clearly, visiting a doctor is the only way to get that prescription. So what can you do with the results of an at-home vision test?
If you’ve never been diagnosed with myopia, your test results could highlight a problem that is new to you, and that should be brought to the attention of a doctor. New symptoms like this could be indicative of a new and serious health problem that your doctor could help you to solve.
If you’ve been diagnosed with myopia in the past, your test results could demonstrate that your problem is getting worse. That could prompt you to visit your doctor to discuss a new prescription, so you can see clearly.
If you’ve been diagnosed with myopia in the past and your test results show that your vision is stable, it could be time to talk with your doctor about LASIK. This surgical procedure uses lasers to reshape the cornea, and it can help to deliver crisp vision to people with myopia. Surgery is only offered to people with stable myopia prescriptions, so monitoring your vision could be a smart way to see if it’s time to start that talk.
At NVISION, we believe in the power of examinations. That is why we offer all of our patients comprehensive examinations before we suggest any kind of vision solution, including surgery. We can help you understand your at-home test results and build on what you’ve learned with powerful diagnostic techniques. Contact us to schedule an appointment.
- Facts About Myopia. (October 2017). National Eye Institute.
- Home Eye Test for Children and Adults. (December 2016). American Academy of Ophthalmology.
- What’s Your Risk of a Vision Problem? Prevent Blindness.
- Nearsightedness: Myopia Diagnosis. (September 2013). American Academy of Ophthalmology.
- Prescription Glasses and Contact Lenses. (April 2016). Federal Trade Commission.
- How to Read Your Eyeglass Prescription. (November 2011). Medicine Net.