Myopia (Nearsightedness)

DEFINITION

Nearsightedness, medically known as myopia, is a highly prevalent condition where the eye has difficulty focusing on objects located far away. While near-work such as reading or mobile use often functions normally, objects at a distance (such as road signs or a classroom whiteboard) appear blurred or hazy. Myopia occurs when the eye refracts light too strongly relative to the eye's length.

SYMPTOMS

The clinical signs of nearsightedness can vary between individuals but often include:

• Blurred or hazy vision when looking at distant objects.
• A need to squint the eyes to see clearly at a distance.
• Headaches caused by persistent strain of the eye muscles.
• Eye fatigue (asthenopia), especially after driving or playing sports.
• Difficulty seeing clearly in low light conditions or during night driving.

When to see an optometrist or doctor: If vision changes affect your ability to perform daily tasks, you should book an eye exam. Emergency medical care is required if you experience sudden flashes of light or many new "floaters" in your vision, as this could be a sign of retinal detachment.

CAUSES AND PATHOGENESIS

Myopia is caused by a biological imbalance in the eye's optical system. The pathogenesis typically involves two main mechanisms:

1. Axial Myopia: The eyeball is too long from front to back. This causes light rays to converge at a focal point in front of the retina instead of directly on it.
2. Refractive Myopia: The cornea or lens has an overly curved surface, leading to excessive light refraction.

The result is that the image sent to the brain is out of focus when the object is far away.

RISK FACTORS

The development of nearsightedness is influenced by both heredity and environment:

• Genetics: If one or both parents are nearsighted, the likelihood that their children will also develop the condition increases.
• Near-work: Prolonged focus on short distances, such as reading, writing, or intensive screen use, is linked to an increased risk of myopia development.
• Lack of Outdoor Activity: Research suggests that daylight and visual stimuli at long distances outdoors have a protective effect, especially during a child's growth phase.

COMPLICATIONS

While most cases of nearsightedness are easily corrected, high myopia (over -6.00 diopters) can lead to serious eye diseases later in life:

• Retinal Detachment: The elongated eyeball stretches the retina, making it thinner and more prone to tears.
• Glaucoma: Nearsighted individuals have a statistically higher risk of increased pressure within the eye.
• Cataracts: Clouding of the lens can occur earlier in people with severe nearsightedness.
• Myopic Macular Degeneration: Damage to the sharp-vision area (macula) as a result of stretching of the eye wall.

DIAGNOSIS

Nearsightedness is diagnosed through a standard eye examination. An optometrist or ophthalmologist uses various tests:

• Refraction Test: Use of a phoropter or autorefractor to objectively measure the refractive error.
• Visual Acuity Test: Reading letters on a Snellen chart to measure visual sharpness.
• Ocular Health Check: Examination of the retina and intraocular pressure to rule out complications.

TREATMENT

The goal of treatment is to move the focal point back onto the retina so that distant objects become clear.

1. Eyeglasses: The simplest and most common correction. Concave lenses (minus lenses) spread the light before it hits the eye.
2. Contact Lenses: Provide a wider field of view and are practical for sports, but require good hygiene.
3. Refractive Surgery: Laser treatment (such as LASIK or FS-LASIK) permanently reshapes the cornea to correct the refractive error. This is usually only an option for adults with stable vision.
4. Ortho-K (Night Lenses): Special lenses worn at night to temporarily change the shape of the cornea.

LIFESTYLE AND PREVENTION

To contribute to good ocular health and potentially slow the progression of nearsightedness, especially in children and young people, the following are recommended:

• 20-20-20 Rule: Every 20 minutes, look at something at least 20 feet (6 meters) away for at least 20 seconds.
• Daylight: Ensure children spend at least 1.5 to 2 hours outdoors every day.
• Good Lighting: Ensure sufficient light during reading and work.
• Ergonomics: Keep screens and books at a good distance from the eyes (approx. 30-40 cm).