Contra-indications, Complications, and Scope of Practice

Why Contra-indications and Complications Matter

Contact lenses sit directly on the ocular surface, making them one of the most intimate medical devices a patient wears. As an optician or contact lens fitter, your job is not only to fit lenses well but also to recognize when fitting is unsafe and when a patient's eye demands immediate professional attention. This lesson defines the boundaries of your clinical role, introduces the conditions that make contact lens wear risky or impossible, and describes the complications you must be able to recognize and act upon.

Systemic Contra-indications

Certain whole-body conditions reduce a patient's ability to wear contact lenses safely.

Immune-suppressing conditions. Diseases or medications that weaken the immune system — such as uncontrolled diabetes mellitus, autoimmune disorders, or long-term systemic corticosteroid use — impair the eye's defense against infection. Microbial keratitis, which can permanently scar the cornea, occurs more readily in these patients.

Severe dry-eye systemic causes. Sjögren's syndrome, rheumatoid arthritis, and certain antihistamines, antidepressants, or diuretics reduce tear volume and quality. An already compromised tear film cannot adequately lubricate or flush a contact lens.

Pregnancy. Corneal curvature and thickness can shift during pregnancy, making a previously successful fit unstable or uncomfortable. Fitting new patients during pregnancy is generally deferred.

Inability to comply. Cognitive limitations, severe manual dexterity problems, or poor personal hygiene that cannot be addressed with training make safe lens handling unlikely.

Ocular Contra-indications

Active ocular infection or inflammation. Any current bacterial, viral, or fungal infection of the eye — including conjunctivitis, keratitis, or uveitis — is an absolute contraindication until fully resolved and cleared by the prescribing provider.

Severe dry eye disease. Clinically significant aqueous-deficient or evaporative dry eye that does not respond adequately to treatment leaves the cornea vulnerable to hypoxic stress and abrasion under a lens.

Corneal compromise. Significant corneal scarring, irregular corneas from keratoconus (unless specialty lenses are prescribed by the doctor), corneal dystrophies, and history of certain corneal surgeries require individualized prescriber evaluation rather than routine fitting.

History of recurrent erosions or herpes simplex keratitis. Contact lens wear can trigger recurrence; these patients need prescriber clearance.

Insufficient lid closure (lagophthalmos). If the cornea is not fully protected during sleep or even blinking, lens wear increases exposure risk markedly.

Recognizing Common Complications

Knowing these complications by their signs and likely causes prepares you to describe what you observe accurately when you communicate with the prescribing optometrist or ophthalmologist.

Giant Papillary Conjunctivitis (GPC). Large papillae (bumps) on the upper tarsal conjunctiva, itching, mucus, and lens intolerance. Caused by mechanical irritation from the lens edge or deposited protein. Action: report findings to the prescriber; lens wear is typically suspended or modified.

Contact Lens Peripheral Ulcer (CLPU). A small, round, peripheral, sterile infiltrate with a clear overlying epithelium, usually associated with gram-positive bacterial toxins from lens deposits or overnight wear. Distinguish from infectious ulcers, which tend to be more central, larger, and accompanied by pain and discharge. Always refer to the prescriber.

Sterile Infiltrates. Focal white blood cell accumulations in the corneal stroma without an infectious organism. Associated with tight lens fit, extended wear, or solution sensitivity. Refer to prescriber to rule out infection before making any lens change.

Corneal Neovascularization. Superficial blood vessels growing into the normally avascular cornea beyond the limbus. A sign of chronic hypoxia, usually from over-wear or a lens with insufficient oxygen transmissibility. Refer to prescriber; lens wear must be suspended or lens material changed.

Microbial Keratitis. A true corneal infection — the most serious complication of contact lens wear. Signs include pain, photophobia, decreased vision, mucopurulent discharge, and a white infiltrate often with an epithelial defect. This is a same-day referral emergency.

Scope of Practice: What the Optician Does and Does Not Do

Your role as a contact lens fitter — under the direction of a prescribing optometrist or ophthalmologist — includes: verifying a current, valid contact lens prescription; selecting lens parameters consistent with the prescription; instructing the patient in insertion, removal, and care; conducting follow-up assessments of lens fit, visual acuity, and surface health as permitted by state law; and documenting your findings.

Your role does not include: diagnosing ocular disease; prescribing contact lenses; prescribing or recommending medications; managing corneal infections or inflammatory disease; or continuing to fit a patient whose ocular health finding falls outside normal limits without prescriber review.

When in doubt, refer. The cardinal rule in scope of practice is: if the finding is outside the expected normal range for a routine contact lens follow-up, stop and refer. Document what you observed, when, and to whom you communicated it. This protects the patient and protects you legally.

The Referral Decision Framework

Use three tiers when you identify a concerning finding:

1. Immediate same-day referral — Any sign of active infection (microbial keratitis), sudden vision loss, or severe pain.

2. Urgent referral at next appointment — Neovascularization, sterile infiltrates, CLPU, moderate GPC with lens intolerance.

3. Document and monitor with prescriber awareness — Mild GPC without lens intolerance, minor staining within acceptable limits; note in the record and ensure the prescriber reviews at the next scheduled visit.

Never dismiss a patient's complaint of pain, blurred vision, redness, or unusual discharge as trivial. These are the warning signs that distinguish a safe lens-wearing experience from a vision-threatening emergency.