Although millions of people need prescription lenses to help their eyesight, not everyone knows exactly how they work or what kind of vision problem they’re addressing.
If you’re having trouble with your eyesight, you might be asking yourself: Am I nearsighted or farsighted? How do I read my eye prescription? What if my vision is blurry both close up and far away?
An eye exam with an optometrist will definitely answer these questions and more. But when it comes to nearsightedness vs. farsightedness, we can help you go a little deeper before your appointment.
How Do Your Eyes Work?
Your eyes convey images to your brain by bending and focusing light onto their retinas.
In an eye with no vision problems, light shines through the cornea (the transparent dome covering the front of your eyeball) and enters the interior of the eye through the pupil. On its way, the light passes through the cornea and then the lens, which sits behind the iris. Both the cornea and the lens focus the light so that it lands squarely on the retina at the back of the eye.
The retina is covered in light-sensitive cells that send information to your brain through the optic nerve. Your brain then interprets the information it receives from the retina as an image.
The above process happens so fast that we perceive “seeing” as an instantaneous act. But as you can see (pardon the wordplay), it actually involves several steps and many different parts of the eye.
Nearsightedness vs. Farsightedness: Causes and Symptoms
Now that you know how your eyeballs produce images in your brain, you’re better positioned to understand nearsightedness and farsightedness. Both of these eye conditions are considered refractive errors—that is, they’re caused by light refracting improperly within the eye so that it doesn’t land right on the retina.
What Do Nearsightedness and Farsightedness Have in Common?
Nearsightedness and farsightedness are both refractive errors caused by the shape of the eyeball or the curvature of the cornea. They share certain symptoms, such as eye strain, headaches, and squinting.
In many ways, they are “reflections” of one another—they’re the same type of problem taking a slightly different shape.
What is Nearsightedness?
Nearsightedness occurs when nearby objects appear more clear than distant ones. When you’re nearsighted, you typically see close-up things in more detail.
What is Farsightedness?
Farsightedness occurs when distant objects appear more clear than nearby ones. When you’re farsighted, you typically see better when focusing on things that are farther away.
How Does Nearsightedness Happen?
Nearsightedness (or myopia) happens when light focuses in front of the retina rather than on it. This can occur because the eyeball is a bit elongated rather than spherical, or because the cornea is curved a bit too steeply.
Light that focuses in front of the retina will still give information to the brain, but the resulting image won’t be as clear, especially when you’re trying to view distant objects.
How Can You Tell if You’re Nearsighted?
The symptoms of nearsightedness include:
- Blurry vision, especially when you’re looking far away
- Eye strain and eye fatigue
- Reduced visual acuity at night
- Squinting to make your eyesight clearer
Not everyone experiences nearsightedness the same way. For example, some variations of nearsightedness can affect your near vision as well as your distance vision.
How Does Farsightedness Happen?
Farsightedness (or hyperopia) happens when the shape of your eye or the curve of your cornea causes light to focus behind the retina rather than on it. Eyes with farsightedness are often a bit short in length instead of spherical, or have a cornea whose curvature is too flat.
When light focuses behind the retina, you aren’t able to see close-up objects as clearly.
How Can You Tell if You’re Farsighted?
The symptoms of farsightedness include:
- Blurry vision, especially when you’re looking at close-up objects
- Eye strain and eye fatigue
- Difficulty reading
- Inaccurate depth perception
Farsightedness can impact your distance vision, too—it’s not limited solely to close-up work.
If you’re experiencing any of the above symptoms of nearsightedness or farsightedness, schedule an eye exam to see which refractive error(s) you have.
A Nearsightedness vs. Farsightedness Diagram
If you’re trying to tell whether you’re farsighted vs. nearsighted, it can be helpful to look at the Venn diagram below.
Common Questions About Being Farsighted vs. Nearsighted
Is It Better to be Nearsighted or Farsighted?
Neither condition is “better” than the other. With the proper vision correction, nearsightedness or farsightedness should not dramatically affect your quality of life.
Is It Rarer to be Nearsighted or Farsighted?
Nearsightedness is more common—about 40% of Americans are nearsighted, whereas 5–10% are farsighted—but both refractive errors are easily treatable.
Can You Be Nearsighted and Farsighted?
You can be nearsighted and farsighted, but not in the same eye. One eye can have nearsightedness while the other has farsightedness. This condition is called antimetropia, and it’s very rare, showing up in only about 0.1% of student groups studied.
How Do You Treat Nearsightedness and Farsightedness?
Both nearsightedness and farsightedness can be treated with corrective lenses—that is, prescription glasses or contacts. Your optometrist can determine your eye prescription after an exam and let you know how strong these lenses need to be.
If you’re nearsighted, you’ll see negative numbers with a minus sign (-) on your eye prescription. If you’re farsighted, you’ll see positive numbers with a plus sign (+). In either case, the further away the numbers are from zero, the more powerful your lenses will be.
Some people opt to correct nearsightedness or farsightedness with other treatments, including surgery (such as LASIK and PRK) or orthokeratology (contacts worn overnight that reshape the cornea, used primarily for nearsightedness correction).
For the majority of people with myopia or hyperopia, however, glasses and contacts remain the most affordable and convenient option.
What’s the Difference Between Being Nearsighted or Farsighted and Having Astigmatism?
Although nearsightedness, farsightedness, and astigmatism are all refractive errors, they have different causes and symptoms.
An eye with astigmatism has an unevenly curved cornea, which causes light to refract into multiple focal points within the eye. Nearsighted and farsighted eyeballs are typically either too long or too short respectively, which causes light to culminate in a single focal point in front of or behind the retina.
Are Reading Glasses for Nearsightedness or Farsightedness?
Reading glasses most often help with presbyopia, which is different from nearsightedness (myopia) and farsightedness (hyperopia). Presbyopia affects all eyes as they age, and causes the lens of the eye to become thicker and less flexible, resulting in blurry close-up vision.
Although this is also a symptom of farsightedness, presbyopia is a separate condition. That said, some people may correct farsightedness with reading glasses, assuming their farsightedness was mild enough not to warrant prescription glasses for everyday use.
Nearsighted or Farsighted, You Have Lots of Options
Hopefully, knowing the difference between farsighted and nearsighted symptoms will help you decide on questions to ask your optometrist. But remember: Only a comprehensive eye exam can tell you for sure which refractive error you have.
Once you have your prescription, it’s time to decide how you’ll correct your vision. Will you sport stylish glasses, go for subtle contacts, or switch between them and get the benefits of each?
No matter what you choose, we hope to help your eyes however we can.