Nearsighted vs. Farsighted: What's the Difference?

What causes nearsightedness and farsightedness?

Both conditions are refractive errors — meaning the eye does not bend (refract) light in a way that brings it to a sharp focus on the retina.

Nearsightedness (myopia) occurs when the eye is slightly too long from front to back, or the cornea is too curved. Light rays from distant objects focus in front of the retina instead of on it, producing a blurry image. Objects close to the eye still focus correctly, which is why near vision stays clear 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Definitions, mechanisms, and correction methods for myopia and hyperopia including cycloplegic refraction and refractive surgery eligibility.

Farsightedness (hyperopia) occurs when the eye is slightly shorter than ideal, or the cornea has too little curvature. Light rays focus behind the retina. The eye can often compensate by contracting the lens (a process called accommodation), so many people with mild hyperopia actually see reasonably well at both distances — particularly when young. But this constant effort of accommodation causes eyestrain, headaches, and eventually blurry vision, especially for close work [1, 2].

What are the symptoms of each?

Myopia symptoms: - Distant objects look blurry or hazy (road signs, the board at school, faces across a room) - Squinting at things far away - Headaches from straining to see at a distance - Difficulty seeing well when driving, particularly at night - No problem reading up close

Hyperopia symptoms: - Eyestrain, fatigue, or headaches after reading or close work - Blurry near vision, especially when tired - Difficulty sustaining focus on a page for extended periods - In children: crossed eyes (accommodative esotropia) is sometimes associated with uncorrected hyperopia 2Ref 2Hutchinson AK, Morse CL, Hercinovic A, Cruz OA, Sprunger DT, Repka MX, Lambert SR, Wallace DK; American Academy of Ophthalmology Preferred Practice Pattern Pediatric Ophthalmology/Strabismus Panel (2023).Pediatric Eye Evaluations Preferred Practice Pattern.Pediatric considerations for hyperopia including accommodative esotropia and importance of cycloplegic refraction in children - In older adults (presbyopia is related but distinct): increasing difficulty with close work

An important nuance: young children with hyperopia often have no noticeable symptoms because their accommodative systems are so flexible. This is one reason routine pediatric vision screening and eye exams matter [2, 3].

How are they diagnosed?

Both conditions are identified during a comprehensive eye exam through a process called refraction — the familiar part of an eye exam where you look through lenses and say which is clearer, "one or two." A cycloplegic refraction (using drops that temporarily relax accommodation) is especially important in children and young adults with hyperopia, because the eye's accommodation can mask the true degree of farsightedness [1, 2].

The prescription is written in diopters: - A negative number (e.g., −2.50) indicates myopia - A positive number (e.g., +2.00) indicates hyperopia - Many prescriptions also include astigmatism (an additional refractive error caused by an irregularly shaped cornea or lens), which often coexists with either

How are they corrected?

Glasses remain the simplest and safest correction for both conditions. For myopia, concave (diverging) lenses are used. For hyperopia, convex (converging) lenses are used 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Definitions, mechanisms, and correction methods for myopia and hyperopia including cycloplegic refraction and refractive surgery eligibility.

Contact lenses correct both conditions with similar optical principles, in rigid or soft lens designs.

Refractive surgery (such as LASIK, LASEK, or PRK) reshapes the cornea to reduce or eliminate the refractive error. These procedures are performed in adults whose prescription has been stable for at least one to two years. They are appropriate for a range of myopia and hyperopia prescriptions, though eligibility depends on corneal thickness and other factors that a refractive surgeon evaluates 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Definitions, mechanisms, and correction methods for myopia and hyperopia including cycloplegic refraction and refractive surgery eligibility.

For children, glasses are the standard approach. Contact lenses and surgery are generally deferred until the prescription stabilizes.

A note on presbyopia (not the same as hyperopia)

Many adults in their 40s notice they need to hold their phone or a book at arm's length to read. This is presbyopia — a normal age-related stiffening of the lens that reduces its ability to accommodate for near vision. Presbyopia is not hyperopia, though both affect near vision. It happens to nearly everyone, including people who are nearsighted.

People with myopia who remove their glasses to read in their 40s or 50s are actually using their myopia to their advantage — their unaided close focus distance compensates for the loss of accommodation. This is often confusing but is entirely normal 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Definitions, mechanisms, and correction methods for myopia and hyperopia including cycloplegic refraction and refractive surgery eligibility.