Contact lenses offer incredible freedom from glasses, but if you’re considering LASIK or other laser eye surgery, you’ll need to temporarily break up with them. One of the most common instructions given to prospective patients is to stop wearing their contact lenses for at least seven days before their pre-operative assessment. But why is this seemingly simple step so crucial for a successful outcome?

The “Why” Behind the Waiting Period

The primary reason for this seven-day hiatus is to allow your cornea to return to its natural, uncompromised shape. Here’s a breakdown of what’s happening:

• Corneal Reshaping: Contact lenses, especially soft lenses, sit directly on the cornea, the clear front surface of your eye. Over time, they can subtly alter its curvature. Think of it like a memory foam mattress – it adapts to your body’s shape. Similarly, your cornea can “mold” to the contact lens.
• Accurate Measurements are Key: For LASIK and other laser eye surgeries, precise measurements of your corneal curvature are paramount. These measurements, obtained through sophisticated topography and wavefront mapping, guide the laser in reshaping your cornea to correct your vision. If your cornea is still influenced by contact lens wear, these measurements will be inaccurate, leading to an incorrect surgical plan and potentially suboptimal vision correction.
• Epithelial Health: Contact lens wear, particularly extended wear, can sometimes lead to mild swelling or irritation of the corneal epithelium, the outermost layer of the cornea. Giving your eyes a break allows this layer to fully recover and normalise, ensuring a healthier and more stable surface for assessment.
• Minimising Risk of Complications: A healthy, stable corneal surface is essential for a smooth surgical procedure and optimal healing. By ensuring your cornea is in its natural state, you reduce the risk of potential complications during and after surgery.

What Happens During the Seven Days?

During this week-long break, your cornea gradually reverts to its natural, pre-contact lens shape. This allows for:

• True Refractive Error: The assessment will be able to determine your actual refractive error without the influence of the contact lenses masking or altering it.
• Accurate Corneal Topography: The maps of your corneal surface will be precise, guiding the laser to the exact points needed for correction.
• Reliable Wavefront Aberrometry: This advanced measurement identifies subtle imperfections in your visual system, and it’s crucial for achieving the best possible visual outcome. These measurements are most accurate when the cornea is in its natural state.

What if I Don’t Stop Wearing Them?

If you don’t adhere to the seven-day rule, your ophthalmologist may need to reschedule your assessment. Attempting to proceed with inaccurate measurements could lead to:

• Overcorrection or Undercorrection: The laser might remove too much or too little tissue, resulting in persistent refractive error.
• Induced Astigmatism: New or increased astigmatism could develop.
• Less Than Optimal Vision: You might not achieve the sharpest or clearest vision possible.

The Takeaway

While it might feel inconvenient to go back to glasses for a week, remember that this short sacrifice is a critical step towards achieving excellent vision without corrective lenses. It ensures that your pre-operative assessment provides the most accurate data, leading to a personalised and successful laser eye surgery experience. Always follow your surgeon’s pre-operative instructions diligently – they are designed with your safety and optimal outcome in mind.