LASIK (Laser-Assisted In Situ Keratomileusis) is a widely sought-after procedure for correcting vision, allowing many people to achieve clear sight without glasses or contact lenses. Preparation requires careful attention to detail for the best possible outcome. A mandatory step is discontinuing contact lens wear because these devices directly influence the eye’s anatomy. Understanding the precise timeline and the scientific reasons behind this requirement is paramount to ensuring a successful procedure.
Determining Your Pre-Surgery Timeline
The required period without contact lenses is not uniform; it depends entirely on the material and design of the lens being worn. This waiting period is known as the “washout” phase, which enables the cornea to stabilize before diagnostic measurements are taken. For standard soft contact lenses, a minimum discontinuation period of one to two weeks is advised before the pre-operative consultation and surgery.
Lenses designed to correct astigmatism, such as toric soft lenses, often require a slightly longer break, usually between two and three weeks. This extended time is necessary because toric lenses can be thicker or have a more rigid structure that exerts greater pressure on the corneal surface.
The most significant waiting period applies to those who wear Rigid Gas Permeable (RGP) or hard contact lenses. Since RGP lenses are made of a firmer material and have a more pronounced effect on corneal shape, surgeons recommend stopping their use for a minimum of three to four weeks. For patients who have worn RGP lenses for decades, the required time can be even longer, sometimes necessitating a week out of the lenses for every decade of use. The specific instructions from your LASIK surgeon should serve as the definitive guide, as protocols can vary slightly between practices.
Why Contact Lenses Affect Corneal Shape
The core reason for the washout period is corneal molding or warping. Contact lenses apply a subtle but constant pressure on the cornea, causing it to temporarily conform to the lens shape. This effect is often combined with a reduction in oxygen reaching the corneal tissue.
LASIK works by using a laser to precisely reshape the cornea to correct refractive error. The success of the procedure relies heavily on obtaining an accurate and stable baseline measurement of the cornea’s natural curvature and thickness. Specialized tests like corneal topography map the eye’s surface to create a customized treatment plan.
If the cornea is still warped when these measurements are taken, the resulting data will be inaccurate. Programming the laser with distorted measurements could lead to an incorrect amount of tissue removal, resulting in under-correction, over-correction, or new visual imperfections. The waiting period ensures the cornea has fully returned to its natural, stable shape, providing the surgeon with reliable data for optimal surgical precision.
Preparing for Your Pre-Op Appointment
Managing the washout period requires a practical approach to vision correction, as you must rely solely on glasses once contact lens use is suspended. Ensure your current eyeglass prescription is up-to-date and the frames are comfortable for continuous wear. Some patients may be advised to switch from RGP lenses to soft lenses for a period before completely discontinuing all contact lens wear to help the cornea begin stabilization.
The pre-operative appointment serves as the final measurement and stability check before the procedure. During this visit, the surgeon will perform a series of tests, including repeated corneal topography and pachymetry, which measures corneal thickness. These measurements are compared to earlier readings to confirm that the corneal shape is stable and fully recovered from the effects of the contact lenses.
If diagnostic tests reveal the cornea is still unstable or changing shape, the surgery will be postponed. Non-compliance with the required waiting period is a common cause for such delays, as the surgeon cannot proceed based on unreliable data. Patients should also avoid using eye makeup, lotions, or creams on the day of the appointment to prevent residue from interfering with the diagnostic equipment. Planning for transportation is necessary, as the pre-operative exam may include pupil dilation, which temporarily impairs driving ability.