Refractive Errors

Myopia

Myopia, or nearsightedness, is one of the most common eye conditions. Individuals with myopia can see nearby objects clearly but struggle to see distant objects, which appear blurry.

Causes of Myopia:

• Elongated eye shape: Light rays fail to focus on the retina.
• Genetic factors: A higher risk exists for individuals with parents who have myopia.

Symptoms of Myopia:

• Blurred vision of distant objects.
• Frequent squinting to see far away.
• Headaches caused by eye strain.
• Discomfort while driving or engaging in sports.

Types of Myopia by Degree:

• Mild myopia: -0.5D to -3D
• Moderate myopia: -3D to -6D
• High myopia: -6D and above

Correction Methods:

• Glasses or contact lenses.
• Laser vision correction, a safe and effective procedure.
• Phakic lens implantation, particularly for high-degree myopia.
• Orthokeratology (night lenses).

Astigmatism

Astigmatism, derived from Latin, means "absence of a focal point."

In a healthy eye, the cornea and lens have smooth, spherical surfaces. In astigmatism, irregularities in the corneal surface cause blurry vision.

Symptoms of Astigmatism:

• Blurry vision both near and far.
• Frequent need to squint.
• Discomfort and headaches.

Astigmatism can be simple, compound, or mixed, often combined with other refractive errors like myopia or hyperopia.

Correction Methods:

• Glasses or contact lenses.
• Laser vision correction.
• Phakic lens implantation.

Hyperopia

Hyperopia, or farsightedness, is a refractive error where images focus behind the retina. This condition is caused by a shorter eye axis or weak refractive power of the cornea and lens.

Symptoms of Moderate to Severe Hyperopia:

• Poor near vision.
• Eye fatigue during reading.
• Eye strain while working (headaches, burning sensation).
• In children: strabismus or lazy eye.

Correction Methods:

• Glasses or contact lenses
• Laser vision correction