Myopia

Synonyms

Also known as Nearsightedness or shortsightedness

Overview

Myopia, commonly known as nearsightedness, is a vision condition where distant objects appear blurry while close objects remain clear. This condition affects individuals of all ages, although it often begins in childhood and tends to progress during adolescence. Genetic predisposition and factors like excessive screen time and near-work are believed to play a role in myopia development. Symptoms of myopia include squinting, headaches, and difficulty seeing distant objects, while close-up tasks are typically easier. Routine eye exams are a crucial step in managing myopia. They allow for early detection and intervention, preventing potential complications. Treatment options include prescription glasses, contact lenses, or surgical options like LASIK.

Key Facts

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Symptoms

Myopia, commonly known as nearsightedness, is a prevalent refractive error of the eye that blurs distant objects while allowing close objects to be seen clearly. Typically emerging in childhood or adolescence, its severity tends to increase until adulthood, where it may stabilize or, in some cases, improve. The symptoms of myopia can vary from person to person but commonly include:

  • Eyestrain
  • Headaches
  • Squinting when reading the board or watching TV
  • Sitting near the TV or computer screen
  • Excessive blinking
  • Rubbing eyes frequently
  • Difficulty seeing objects far away, such as road signs or a blackboard at school

Cause

Myopia primarily arises from an elongation of the eyeball, disrupting the normal focusing mechanism of the cornea (front part of the eye) and impacting how light is directed onto the retina (back of the eye), which is crucial for clear vision.

Several factors contribute to proper light focusing onto the retina:

  • Eye length from front to back
  • Shape of the cornea and lens
  • Alignment of the lens and cornea within the eye

Minor variations in these factors can trigger myopia, as they affect the precise bending of light rays necessary for clear vision.

RiskFactors

Several factors contribute to the development and progression of myopia:

  • Parental myopia: Having one or both myopic parents significantly increases the risk of juvenile-onset myopia, leading to faster progression.
  • Environmental factors: Certain environmental factors, particularly those involving close-up work or limited time spent outdoors, can increase the risk of developing myopia. These factors include:
    • Prolonged eye strain: Spending long hours reading, using computers, or doing other close-up work can increase the risk of myopia, especially during childhood and adolescence.
    • Extensive screen time: Extensive exposure to TV, mobile phones, and gaming contributes to myopia development.
    • Limited outdoor exposure: Spending less time outdoors, especially during childhood, has been associated with a higher risk of myopia development. Outdoor exposure to natural light may have a protective effect against myopia.
    • Urbanization: Myopia rates tend to be higher in urban areas compared to rural areas, possibly due to differences in lifestyle and environmental factors.
  • Age: Myopia commonly develops during childhood or adolescence, peaking in the late teens or early twenties. Though the risk diminishes with age, some individuals experience ongoing progression into adulthood.
  • Nutrition: Studies suggest that diets high in processed foods and low in fruits and vegetables may increase myopia risk, though further research is needed for conclusive evidence.

Diagnosis

Nearsightedness, or myopia, is typically diagnosed through a comprehensive eye examination performed by an optometrist or ophthalmologist. The diagnostic process for myopia usually involves the following tests:

  • Visual acuity test: This test measures how well you can see at various distances. You'll be asked to read letters or symbols from a chart at a standardized distance. If you have myopia, you may have difficulty reading letters or seeing objects clearly at a distance.
  • Refraction test: During this test, the eye care professional uses a phoropter or a handheld instrument called a retinoscope to determine the precise optical power needed to correct your vision. This test assesses the sharpness and clarity of vision. Both eyes are tested individually for their ability to see letters of varying sizes.
  • Retinoscopy: This involves shining a light into your eyes and observing how it bounces back. By adjusting the power of the light, the eye doctor can determine if you're nearsighted (myopic) and the strength of your prescription needs.
  • Auto refractometer: This high-tech gadget quickly and accurately measures your prescription using invisible light, requiring no action on your part. It benefits screening people with myopia and has almost replaced traditional retinoscopy for routine checks.
  • Corneal topography: This step is crucial for detecting cornea-related issues in myopic patients and helps determine suitability for laser eye surgery. Machines like Orbscan or Pentacam provide detailed maps of your cornea's shape and thickness, aiding eye surgeons in planning the best treatment.
  • Slit-lamp examination: This involves looking closely at your eyes with a special microscope called a slit lamp. This examination offers a detailed view of your eye's structures, including the cornea, lens, and retina, helping to identify any abnormalities associated with myopia.
  • Additional tests: In some cases, additional tests may be performed to evaluate specific eye health or vision aspects. These tests may include measuring intraocular pressure (tonometry) to screen for glaucoma or assessing the cornea's curvature (keratometry) to determine the shape of the eye's surface.

Regular eye examinations are essential, especially if you notice changes in your vision or if you have a family history of eye conditions like myopia. Early detection and management can help prevent complications and maintain optimal eye health.

Prevention

Preventing Myopia is challenging due to its familial link. However, the following measures can help reduce the likelihood of developing nearsightedness:

  • Outdoor activities: Encourage children to take charge of their eye health by spending more time outdoors. Studies suggest that increased exposure to natural light may help reduce the risk of Myopia. Doctors recommend 60-80 minutes of outdoor play per day to allow natural light to enter the eyes, relax eye muscles, and promote healthy habits.
  • Limit screen time: Reduce prolonged near-work activities, such as reading or screen time, especially in young children. Encourage breaks and frequent focus shifts to prevent eye strain.
  • Follow the 20-20-20 rule: Take breaks every 20 minutes and look at something 20 feet away for at least 20 seconds to reduce eye strain from prolonged near work.
  • Ensure proper lighting: Maintain adequate lighting when reading or performing close-up tasks to reduce eye strain and promote comfortable vision.
  • Consume a healthy diet: A balanced diet rich in the following nutrients is beneficial for eye health and can contribute to preventing Myopia:
    • Vitamin A: Found in carrots, sweet potatoes, cantaloupe, and apricots, vitamin A is essential for retinal health. It supports clear vision and prevents dry eyes.
    • Vitamin C: Acting as a powerful antioxidant, it shields against cellular damage, aids in eye tissue repair, and helps prevent age-related degeneration of eyes and cataracts. Rich sources include oranges, tangerines, grapefruits, peaches, red bell peppers, and tomatoes.
    • Vitamin E: Promotes cell health, acts as an antioxidant to combat oxidative stress, and contributes to overall eye health. Avocados, almonds, and sunflower seeds are excellent sources.
    • Omega-3 fatty acids: Help reduce the risk of eye diseases like AMD, improve tear function, and support overall eye health. Rich sources include salmon, tuna, sardines, halibut, and trout.
    • Lutein and Zeaxanthin: Crucial antioxidants for maintaining vision and reducing the risk of age-related vision disorders. Foods like kale, spinach, romaine lettuce, collards, turnip greens, broccoli, and peas are rich in these nutrients.
    • Zinc: Supports retinal health, protects the eyes from light-induced damage, and helps maintain overall eye function. It can be obtained from beans (black-eyed peas, kidney beans, lima beans), oysters, lean red meat, poultry, and fortified cereals.
  • Regular eye exams: Routine eye examinations with an optometrist or ophthalmologist, especially for children, help detect Myopia early, leading to timely and appropriate management.

Recommended Examination Frequency for Eye Check-ups

For Children and Teenagers

  • Eye exams should be conducted at birth, between 6 and 12 months, and again between 12 and 36 months.
  • Subsequent screenings should occur at least once between ages 3 and 5, before starting kindergarten, and annually through the end of high school.

For Adults

  • Healthy adults with no known vision issues or eye diseases should have a comprehensive eye exam:
    • At least once between ages 20 and 29.
    • At least twice between ages 30 and 39.
    • Every 2 to 4 years from ages 40 to 54.
    • Every 1 to 3 years from ages 55 to 64.
    • Every 1 to 2 years after age 65.

Remember!

Regular and frequent eye exams are crucial for those with diabetes, a family history of eye issues, or high blood pressure. These screenings play a significant role in early detection and prevention. Similarly, individuals with prior vision corrections or surgeries should adhere to regular check-ups as advised by their doctor or eye specialist.

Treatment

Myopia treatment options can be divided into non-surgical and surgical approaches.

I. Non-Surgical Treatment

Eyeglasses

  • Eyeglasses are prescribed with concave lenses to compensate for the elongated eyeball shape typical in myopic individuals.
  • Depending on the severity, glasses may be used full-time or for specific activities like driving or watching TV.
  • Bifocal or progressive lenses may be necessary for individuals over 40 with presbyopia, a condition where it becomes difficult to focus on close objects.

Contact Lenses

II. Surgical Treatment

LASIK

  • LASIK involves creating a corneal flap and reshaping tissue with a laser to correct nearsightedness.
  • It is preferred for moderate to severe cases, offering rapid recovery and improved vision.

Epi-LASIK (Epithelial Laser-Assisted In Situ Keratomileusis)

  • Epi-LASIK corrects nearsightedness by reshaping the cornea with a laser.
  • It involves gently separating and preserving the corneal epithelium (outer layer) before laser treatment, which can result in a slightly longer recovery time compared to LASIK.

PRK (Photorefractive Keratectomy)

  • PRK removes the corneal epithelium entirely before reshaping tissue with a laser.
  • It is preferred for thin corneas or active individuals involved in contact sports, and it has a longer recovery period.

Phakic Intraocular Lenses

  • Phakic intraocular lenses are implanted in front of the natural lens for high myopia or thin corneas, providing an alternative to corneal surgeries.

Intraocular Lens Implant

  • This surgery involves replacing the natural lens with an artificial one, suitable for those seeking clear vision without glasses or contacts.

SMILE (Small Incision Lenticule Extraction)

  • SMILE is a minimally invasive surgery involving the extraction of a lenticule from the cornea to correct myopia without creating a corneal flap.
  • This procedure potentially reduces complications and recovery time.

Tips for a Swift Recovery After Eye Surgery

  • Follow your doctor's aftercare instructions diligently.
  • Use lubricating eye drops as prescribed to maintain eye health and ease discomfort.
  • If recommended, wear non-prescription sunglasses or goggles temporarily after surgery.
  • Keep your hands clean and avoid dusty environments to prevent infection.
  • Wear UV-protective sunglasses outdoors to protect your eyes.
  • Get enough rest and avoid strenuous activities to aid healing.
  • Arrange for assistance at home as your vision may be blurry after surgery.
  • Do not drive home on the day of surgery; wait for clearance from your medical team.
  • Avoid nighttime driving until your eyes have fully recovered for safety.
  • Take baths instead of showers to prevent water from entering your eyes.

Complications

While myopia is generally manageable with corrective lenses or surgery, proactive management is essential to prevent potential complications associated with high levels of myopia or if left untreated. Some potential complications include:

  • Retinal detachment: Myopia increases the risk of retinal detachment, where the thin layer of tissue at the back of the eye detaches from its normal position, leading to vision loss if not promptly treated.
  • Macular degeneration: High myopia is associated with an increased risk of developing age-related macular degeneration, a progressive condition affecting the central part of the retina (macula), leading to central vision loss.
  • Glaucoma: Myopia is a risk factor for glaucoma, a group of eye diseases that damage the optic nerve, often resulting in irreversible vision loss if left untreated.
  • Cataracts: Myopia may increase the likelihood of developing cataracts, a clouding of the eye's natural lens, which, if untreated, can lead to blurred vision and eventual vision loss.
  • Strabismus and amblyopia: Severe myopia can cause misalignment of the eyes (strabismus) and reduced vision in one eye (amblyopia), especially if left uncorrected during childhood.
  • Visual disturbances: Myopia may lead to visual disturbances such as halos, glare, or difficulty seeing in low-light conditions, impacting quality of life and visual comfort.
  • Posterior capsule opacification (PCO): Thickening of the lens capsule leading to cloudy vision is a potential complication following myopia surgery, requiring corrective measures such as laser capsulotomy to restore clarity of vision.

References

American Academy of Ophthalmology
National Center for Biotechnology Information
2017
National Center for Biotechnology Information
2021
Johns Hopkins Medicine
American Optometric Association
American Academy of Ophthalmology
National Center for Biotechnology Information
2020
American Academy of Ophthalmology
National Center for Biotechnology Information
2020

Frequently asked questions

Bilateral myopia refers to myopia affecting both eyes. Corrective lenses are tailored individually for each eye's prescription to ensure optimal vision clarity.
Myopia can progress over time, particularly during childhood and adolescence, with the rate of progression varying among individuals.
Refractive surgeries like LASIK and PRK can provide permanent correction for myopia by reshaping the cornea, though candidacy depends on various factors and should be discussed with an eye care professional.
Myopia is difficulty seeing distant objects, while hyperopia is difficulty seeing nearby objects. In myopia, images fall in front of the retina, causing blurry distance vision; in hyperopia, images fall behind the retina, leading to blurry near vision.
Myopia causes blurred distance vision as light focuses in front of the retina, while astigmatism results in blurry vision at all distances due to light being focused at multiple points, often caused by uneven curvature of the cornea or lens.
Yes, spending time outdoors, especially in natural sunlight, is linked to a reduced risk of developing and progressing myopia by regulating eyeball growth and promoting overall eye health.
Myopia may stabilize in adulthood for some individuals after progressing during childhood and adolescence. Regular eye examinations are crucial to monitor vision changes and ensure timely intervention if necessary.