LASIK (Laser-Assisted In Situ Keratomileusis) is a surgical procedure designed to correct common refractive errors, offering freedom from glasses and contact lenses. A non-negotiable step in preparation is the complete cessation of contact lens wear. This pre-operative preparation ensures the safety and accuracy of the procedure. The required contact-free period allows the eye to return to its natural, stable state, which is necessary for precise surgical planning.
How Contact Lenses Alter Corneal Shape
Contact lenses, whether soft or rigid, sit directly on the cornea, the clear, dome-shaped front surface of the eye. The physical presence of the lens temporarily changes the curvature and shape of this tissue, a phenomenon often referred to as corneal “molding” or warpage. This alteration occurs because the lens exerts pressure on the corneal surface.
A second factor contributing to this change is the reduction of oxygen flow (hypoxia) to the corneal tissue, especially with extended-wear lenses. This can lead to subtle corneal swelling or edema, further distorting the tissue’s natural topography. The cornea must be completely free of these temporary distortions and swelling before any measurements are taken for the laser treatment plan. Allowing the cornea to fully stabilize ensures the underlying tissue is in its most natural state for accurate surgical planning.
Mandatory Cessation Timelines by Lens Type
The exact duration of the contact-free period is determined by the type of lens worn. For most soft contact lens users, the general recommendation is to stop wear for at least one to two weeks before the pre-operative evaluation and surgery.
Toric Lenses
Toric soft lenses, which are designed to correct astigmatism, are typically thicker than standard soft lenses and may require a slightly longer break, often two to three weeks.
Rigid Gas Permeable (RGP) Lenses
Rigid Gas Permeable (RGP) or hard lenses cause a more significant and longer-lasting change to the corneal structure because they exert greater pressure. Individuals who wear RGP lenses must stop wearing them for a minimum of three to four weeks, and sometimes longer, before the initial measurements are taken. The stability of the cornea may need to be confirmed through sequential measurements taken weeks apart before the surgeon approves the final treatment plan.
The Necessity of Accurate Pre-Surgical Mapping
The primary reason for discontinuing contact lens wear is to obtain highly accurate measurements used to program the excimer laser. LASIK relies on advanced diagnostic tools, such as corneal topography and wavefront analysis, to create a precise, customized treatment profile. Corneal topography maps the curvature and shape of the cornea across its entire surface, providing a detailed elevation map.
If the cornea is still temporarily molded by a contact lens, the measurements from these mapping devices will be inaccurate. The laser would then be programmed to treat a shape that is not the eye’s natural resting state. This inaccuracy can lead directly to a suboptimal surgical outcome, potentially resulting in under-correction, over-correction, or the induction of new refractive errors like irregular astigmatism. Allowing the cornea to return to its stable, natural shape ensures that the laser ablation profile precisely matches the patient’s actual refractive error.
Navigating the Contact-Free Period
Adjusting to life without contacts for several weeks requires practical planning. The most straightforward solution is to switch to wearing glasses full-time as soon as the cessation period begins. Patients should ensure they have an up-to-date prescription in comfortable frames to manage their vision needs.
Some patients experience temporary dryness or mild discomfort after stopping contact lens wear, and lubricating eye drops can help manage these symptoms. It is important to attend all scheduled pre-operative appointments, as the surgeon will use these visits to confirm the cornea has fully stabilized and is ready for surgery. Failure to comply with the contact-free period may result in the procedure being postponed until the eye is fully prepared.