Refractive Errors & Refractive Surgery

What Are Refractive Errors?

Refractive errors occur when the shape of the eye prevents light from focusing directly on the retina. Instead, the light focuses either in front of or behind the retina, resulting in blurred vision.

The four most common types of refractive errors are:

1. Myopia (Nearsightedness)
   • Distant objects appear blurry.
   • Caused by an eyeball that’s too long or a cornea that’s too curved.
2. Hyperopia (Farsightedness)
   • Close objects appear blurry.
   • Caused by an eyeball that’s too short or a cornea that’s too flat.
3. Astigmatism
   • Vision is distorted or blurred at all distances.
   • Caused by an irregularly shaped cornea or lens.
4. Presbyopia
   • Age-related condition where the eye gradually loses the ability to focus on close objects.
   • Typically affects people over the age of 40.

While glasses and contact lenses are effective at correcting these issues, they don’t address the root cause. That’s where refractive surgery comes in.

Types of Refractive Surgery

Refractive surgery aims to reshape the cornea or replace the natural lens of the eye to correct vision. The right procedure depends on the type of refractive error, the patient’s age, eye health, and lifestyle.

1. LASIK (Laser-Assisted In Situ Keratomileusis)

• How it works: A laser reshapes the cornea after creating a thin flap in the outer layer.
• Best for: Myopia, hyperopia, and astigmatism.
• Pros: Quick recovery, minimal discomfort, high success rate.
• Considerations: Not ideal for people with very thin corneas or dry eyes.

2. PRK (Photorefractive Keratectomy)

• How it works: The outer layer of the cornea is removed and the underlying tissue is reshaped with a laser.
• Best for: People with thinner corneas or those who can’t have LASIK.
• Pros: No flap created, making it safer for certain eye shapes.
• Considerations: Longer recovery and more discomfort than LASIK.

Is Refractive Surgery Right for You?

While refractive surgery has helped millions achieve 20/20 (or better) vision, it isn't necessarily right for everyone. Ideal candidates are generally:

• Over 18 (ideally mid-20's) with stable vision for at least a year
• Free from certain eye diseases or corneal abnormalities
• Not pregnant or nursing
• In good overall health

A comprehensive eye exam and consultation with an eye surgeon is the only way to know which option is best for you.