If you are one of the millions of Americans who struggle with poor vision, you may be wondering what the numbers on your prescription mean. Realistically, how bad is your vision? What prescription is considered legally blind?

To know how bad your vision is, you must look at the numbers on your prescription. Prescriptions are measured from +/- 0.25, and the larger the number, the worse your vision is. In the United States, a person is considered legally blind if they have 20/200 vision or worse.

Below, we will discuss more detailed information on what the numbers in your prescription mean and other helpful tips. Keep reading to learn everything you need to know about your own vision!

How Can I Tell How Bad My Vision is?

You had your regular eye exam, and the doctor made some adjustments to your prescription. It happens to the best of us. As we age, our vision tends to get a little worse.

When you go to order your new glasses, however, you realize you have no idea what any of the numbers on the paper mean!

When ordering glasses or contact lenses online, it is important that you understand what your prescription means and enter it correctly into the system.

Entering the numbers wrong will lead to glasses that don’t work for your eyes, and it may even make your eyesight worse.

Wearing glasses or contact lenses with the wrong prescription can cause blurriness, eye strain, and headaches.

The following list will explain what the numbers on your prescription mean in terms of your vision:

  • +/- 0.25 to +/- 2.00: Mild vision correction needed.
  • +/- 2.25 to +/- 5.00: Moderate vision correction needed.
  • Over +/- 5.00: Severe vision correction needed.

For many people who fall into the mild correction category, a simple pair of magnifying glasses is usually all they need to get by.

Anyone who falls into the moderate to severe correction category will need prescription lenses to ensure they can see properly and are not straining their eyes.

Either way, it is important to visit your eye doctor regularly to be sure you are wearing the right strength of lenses for your eyes.

What Prescription Qualifies a Person as Legally Blind?

Now that you know how bad your vision is, you may be wondering what it means to qualify as legally blind in the United States.

To be considered legally blind in the United States, your vision must be declared 20/200 by a licensed optometrist. This means that items and writing that most people can clearly see from 200 feet away can only be seen clearly from 20 feet away.

20/20 is considered perfect vision, so a legally blind person’s vision must be at least ten times worse than that of a person with perfect vision.

Other Optical Terms You Should Know

To better understand your prescription and the type of vision you have, it’s helpful to familiarize yourself with a few optical terms.

Some other terms that may help to explain the type of vision you have are:

  • Astigmatism: This has to do with a flawed curvature of the cornea in the eye. Having an astigmatism will cause blurry vision to be blurry from near or far distances.
  • Amblyopia: This is the proper term for having a lazy eye. Some people can even have two lazy eyes.
  • Presbyopia: This occurs naturally as we age. Generally, things will be more difficult to see from a distance or up close. Many also experience difficulty driving after dark.  

Even though some of these terms may seem scary or sound serious, they are very common and can generally be corrected with glasses or contact lenses.

It is possible to correct some of the conditions mentioned above with laser eye surgery if you do not wish to have the hassle of wearing glasses or contact lenses.

In Conclusion

To be considered legally blind, your vision must be ten times worse than a person with average vision. A person with a prescription of 20/200 is considered legally blind in the United States.

Knowing what your prescription means can help you when buying glasses or contacts online, and also help you keep track of your eye health.