Contact lenses are medical devices placed directly onto the surface of the eye to correct vision problems like nearsightedness, farsightedness, and astigmatism. Obtaining these lenses requires a series of distinct steps beyond a typical vision check to ensure the safety, comfort, and long-term health of your eyes. The process is regulated and overseen by an eye care professional, such as an optometrist or ophthalmologist, who ensures the lenses are medically appropriate before a prescription can be issued.
The Comprehensive Eye Exam
The process begins with a comprehensive eye examination to establish a baseline of your overall ocular health. During this initial appointment, the doctor checks for underlying eye diseases or conditions that could complicate contact lens wear, such as glaucoma, cataracts, or severe dry eye. Specialized equipment evaluates the internal and external structures of the eye, including the cornea and retina, ensuring they are healthy enough to support a contact lens.
The refraction test accurately determines your basic visual error. This test establishes the numerical power needed to correct your vision, addressing issues like myopia (nearsightedness) or hyperopia (farsightedness). This initial power is often different from what would be used for a glasses prescription because contact lenses sit directly on the cornea.
Specialized Contact Lens Fitting
The specialized contact lens fitting determines the physical parameters of the lens. The fit is determined by measuring the curvature of the cornea, the clear front surface of the eye, using an instrument called a keratometer or a corneal topographer. These measurements determine the lens’s base curve, which must match the eye’s shape to ensure the lens rests neither too tightly nor too loosely.
The assessment of your tear film quality and quantity is essential for comfortable wear, as the lens floats on this thin layer of fluid. If the tear film is unstable or insufficient, the doctor might recommend lenses made from specific moisture-retaining materials, like silicone hydrogel, to improve hydration. The eye care professional also discusses your lifestyle, recommending a lens type such as daily disposable, monthly replacement, or specialized lenses like toric for astigmatism or multifocal for presbyopia. Trial lenses are then applied so the doctor can assess their movement, alignment, and comfort on the eye before any final prescription is written.
Learning Insertion, Removal, and Care
Once suitable trial lenses are selected, new wearers receive practical training in the proper handling and maintenance of their lenses. This hands-on instruction is paramount for preventing eye infections, as poor hygiene is a leading cause of contact lens-related issues. The training emphasizes handwashing with non-cosmetic, anti-bacterial soap, followed by drying with a lint-free towel before touching the lenses.
The insertion technique involves placing the lens on the tip of a clean, dry index finger, ensuring it is not inside out. To insert, the wearer must use their non-dominant hand to hold the upper eyelid, look straight ahead, and gently place the lens directly onto the eye’s surface. Removal is done by sliding the lens down to the white part of the eye and gently pinching it off with the thumb and index finger, avoiding contact with fingernails.
Care involves using only fresh, recommended disinfecting solution each time the lenses are stored. Lenses that are not daily disposables must be gently rubbed and rinsed with solution after removal to dislodge deposits and microorganisms before being placed in a clean case. Patients are explicitly warned never to use tap water for cleaning or rinsing, as it can harbor a microorganism called Acanthamoeba, which can cause a devastating eye infection. New wearers are also given a gradual wearing schedule to allow their eyes to adapt, and they must never wear lenses longer than prescribed or sleep in lenses unless they are specifically approved for overnight wear.
Prescription Finalization and Ongoing Wear
After the initial training and the provision of trial lenses, a follow-up appointment is scheduled. During this visit, the doctor re-examines the eye to confirm that the lenses are fitting comfortably, providing stable vision, and not causing any adverse reactions, such as corneal swelling or irritation. This check confirms the long-term compatibility of the lens material and fit with the patient’s eyes before the process is considered complete.
Only after this final evaluation is deemed satisfactory can the eye care professional issue a complete contact lens prescription. This prescription is a medical document that must include specific parameters:
- Lens power
- Base curve
- Diameter
- Material
- Brand name
Federal regulations stipulate that a contact lens prescription is valid for a minimum of one year, after which an annual eye examination is required to renew the prescription and ensure continued eye health and safe lens use.