Refractive Errors: Types, Causes,
Symptoms & Treatment Options

Refractive errors are among the most common eye conditions worldwide. They occur when the shape of your eye prevents light from focusing properly on the retina, resulting in blurred vision. Fortunately, these issues are typically easy to correct with eyeglasses, contact lenses, or vision correction surgery.

What Are Refractive Errors?

A refractive error happens when your eye cannot bend (or refract) light correctly, which leads to distorted or blurry vision. This is usually due to abnormalities in the shape of the cornea, lens, or the length of the eyeball.

Refractive errors can affect both children and adults and can develop at any stage of life—even if you previously had perfect vision.

How Does the Eye Normally Work?

The eye works like a camera:

  1. Light enters through the cornea (the eye’s clear front surface).
  2. The lens then focuses that light onto the retina, located at the back of your eye.
  3. The retina converts light into electrical signals.
  4. These signals travel via the optic nerve to your brain, where they’re interpreted as images.

If any part of this process is disrupted by irregular eye shape, it results in a refractive error.

Types of Refractive Errors

1. Nearsightedness (Myopia)

  • Symptoms: Distant objects appear blurry.
  • Cause: The eyeball is too long, or the cornea is too curved.
  • Common in: Children and teenagers.
  • Example: You can read a book clearly, but road signs are blurry.

2. Farsightedness (Hyperopia)

  • Symptoms: Close objects appear blurry.
  • Cause: The eyeball is too short, or the cornea is too flat.
  • Common in: Often present from birth.
  • Example: You can see a screen across the room but struggle to read your phone.

3. Age-related Farsightedness (Presbyopia)

  • Symptoms: Difficulty focusing on close objects as you age.
  • Cause: Lens stiffening with age.
  • Common in: Adults over 40.
  • Solution: Reading glasses or multifocal lenses.

4. Astigmatism

    • Symptoms: Blurred or distorted vision at any distance.
    • Cause: The eye is shaped more like a football than a basketball.
    • Can occur with: Myopia or hyperopia.
    • Example: Objects may appear stretched or wavy.
Symptoms of Refractive Errors
  • Blurry vision (near, far, or both)
  • Squinting
  • Headaches
  • Eye strain or discomfort
  • Double vision (diplopia)
  • Children may show signs such as poor school performance or trouble focusing
Causes of Refractive Errors

Refractive errors are typically caused by:

  • Genetics
  • Irregular eye shape
  • Age-related changes in the lens
  • Eye surgeries (such as cataract removal)
  • Eye growth patterns in children and teens
Diagnosis: How Are Refractive Errors Detected?

Your eye care specialist will perform a comprehensive eye exam, including:

  • Visual acuity tests
  • Retinoscopy
  • Examination of the eye’s internal structures

These tests help determine your prescription and identify the specific type of refractive error you have.

Treatment Options for Refractive Error

Eyeglasses

  • Most common and non-invasive option
  • Can correct all types of refractive errors

Contact Lenses

  • Provide a wider field of vision
  • Great for active individuals or cosmetic preferences

Vision Correction Surgery

  • LASIK (Laser-Assisted In Situ Keratomileusis)
  • ASA (Advance Surface Laser Ablation)
  • PRK (Photorefractive Keratectomy)
  • Reshapes the cornea to correct vision permanently
  • Consult your specialist to see if you’re a candidate
Can Refractive Errors Be Prevented?

Unfortunately, refractive errors can’t be prevented, as they are mostly due to genetics or natural aging. However, early detection and treatment can prevent further vision loss and improve quality of life.

How Often Should You Get an Eye Exam?
  • Children: Every 1–2 years after learning the alphabet
  • Adults under 40: Every 5–10 years
  • Ages 40–54: Every 2–4 years
  • Ages 55+: Every 1–3 years
  • More frequent exams are needed if you wear glasses, have diabetes, or experience vision changes
When to See an Eye Specialist Immediately
  • Sudden vision loss
  • Severe eye pain
  • Flashes of light or new floaters
  • Blurred vision that worsens quickly
Key Takeaways
  • Refractive errors are very common and highly treatable.
  • Most people experience them due to irregular eye shape or aging.
  • Eyeglasses, contacts, and surgical options can restore clear vision.
  • Regular eye exams are essential for early detection and management
Talk to Your Eye Care Specialist

Whether you’re experiencing blurry vision or just need an updated prescription, don’t delay an eye exam. Refractive errors are manageable, and your eye doctor can help you find the best solution for clear, comfortable vision.