If you are farsighted (hyperopia), your vision is poor up close.
If your vision is blurry when reading road signs from a distance, you are nearsighted.
You may also squint in an attempt to see more clearly.
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The critical difference that can help you tell these apart is the distance at which you experience blurry vision.
Causes
Both nearsightedness and farsightedness depend on the shape of the eye and how you see.
The retina then conveys this information to the brain via theoptic nerve.
Illustration by Joules Garcia for Verywell Health
Instead, they land in front of it.
Or, your eye may have an unusually long front-to-back length.
Because of this, the light rays converge in front of the retina instead of onto it.
Nearsightedness tends to run in families.
But genetics is not the only factor.
you could still have nearsighted vision even if it doesn’t affect any of your family members.
However, the other possible causes of it aren’t always clear.
Farsightedness
If you are farsighted, you may have an unusually flat cornea.
Or, your eye is shorter than usual.
Either of these can cause the light rays to land behind the retina instead of focusing directly on it.
If this is mild enough, you may not notice any issues.
If your farsightedness is severe, objects may appear blurry not just up close but at any distance.
However, researchers have also been unable to pinpoint the other possible reasons that farsightedness occurs.
Diagnosis
An ophthalmologist or optometrist can diagnose nearsightedness or farsightedness during a routine comprehensiveeye exam.
They will ask you to read letters from a chart as part of the exam.
To get the right prescription to correct the refractive error, the ophthalmologist may use aphoropterto test your vision.
You look through this instrument through different lenses to determine the best correction.
What is normal vision?
Normal vision is also called20/20 vision.
Treatment
An ophthalmologist or optometrist needs to distinguish nearsightedness from farsightedness.
An eye doctor will often prescribe glasses or contact lenses to sharpen your distance vision if you are nearsighted.
Contact lenses or spectacles focus the light onto the retina where it would ideally land.
But you must consult an eye doctor to see if this is true for your child.
Here are some approaches to consider:
Unfortunately, there is currently no way to prevent farsightedness.
You cannot use vitamins, eye exercises, or medicine to avoid this.
The critical difference between the two is just where the blurriness occurs.
The causes here mirror each other.
With nearsightedness, the cornea is either too steep or the eye is too long.
With farsightedness, the cornea is either too flat or the eye is too short.
National Eye Institute.Nearsightedness (myopia).
American Academy of Ophthalmology.Farsightedness: What is hyperopia?
American Academy of Ophthalmology.Nearsightedness: What is myopia?
American Optometric Association.Visual acuity.
American Academy of Ophthalmology.What is refractive surgery?
University of Rochester Medical Center.Types of eye surgery for refractive errors.
American Academy of Ophthalmology.Myopia control in children.
