Instilling safe contact lens wearing practices in patients

Contact lenses are FDA-regulated medical devices that provide effective refractive correction, therapeutic benefits, and myopia management options for millions of patients. More than 45 million people in the US wear contact lenses, and approximately 1 million seek care annually for contact lens–related complications.^1-4 Although modern lens materials and care systems have improved comfort, oxygen transmission, and ease of use, preventable adverse events remain clinically important because unsafe behaviors are common, often normalized by patients, and frequently underrecognized until symptoms develop. Contact lens–related complications also create a disproportionate clinical burden because an apparently minor lapse, such as sleeping in lenses during travel or topping off solution for convenience, can lead to urgent visits, treatment interruption, corneal scarring, or permanent vision loss. This review summarizes major contact lens risks, solution-related adverse effects, higher-risk populations, and practical prevention strategies for optometric practice, with an emphasis on counseling points that can be incorporated into routine care.

Complications and risk factors

Contact lens complications range from discomfort, dryness, corneal staining, sterile infiltrates, giant papillary conjunctivitis, corneal neovascularization, hypoxia-related edema, and warpage to sight-threatening microbial keratitis. Mild findings may appear routine, but they should be interpreted in the context of wear schedule, lens material, replacement frequency, solution exposure, ocular surface status, and patient behavior. Bacterial keratitis accounts for most contact lens–related infectious keratitis in the United States, with Pseudomonas aeruginosa frequently isolated.^1,5,6 The clinical challenge is that early infectious keratitis may initially resemble a sterile inflammatory event; therefore, pain, photophobia, reduced vision, focal infiltrate, epithelial defect, anterior chamber reaction, or rapidly worsening redness should prompt urgent evaluation and a low threshold for discontinuing lens wear, culturing when indicated, and initiating appropriate therapy.^8-10

Overnight wear is the most important modifiable risk factor, increasing the risk of microbial keratitis approximately 10- to 15-fold compared with daily wear.⁵ This risk is biologically plausible because closed-eye wear reduces oxygen availability, decreases tear exchange, increases lens adherence, and creates a microenvironment that may compromise epithelial integrity and microbial defense. Additional risks include poor hand hygiene, exceeding replacement schedules, topping off solution, inadequate lens case cleaning, infrequent case replacement, and exposure of lenses or cases to tap water, showers, pools, or hot tubs.^7,9 Findings from surveillance studies show that nearly all wearers report at least 1 hygiene risk behavior, reinforcing the need for repeated counseling rather than onetime instruction.^3,4 These behaviors should be addressed directly because many patients do not view occasional nonadherence as dangerous; they may distinguish “just a nap,” “only rinsing the case,” or “only swimming once” from higher-risk behavior even though each can meaningfully increase risk.

Lens modality and care systems

Daily disposable lenses are a safety-forward option because they eliminate the need for storage cases and care solutions, reducing opportunities for contamination and solution-related toxicity.^8,10,11 They are particularly useful for patients with inconsistent hygiene, frequent travel, variable schedules, seasonal allergies, heavy deposit formation, or prior inflammatory events. However, they do not eliminate risk if patients sleep in lenses, expose lenses to water, wear lenses beyond the prescribed single-use schedule, or ignore warning symptoms. Reusable soft lenses, rigid gas permeable lenses, scleral lenses, and orthokeratology all require modality-specific education, strict care routines, and appropriate follow-up. Specialty lenses warrant particular attention because care regimens are more complex and, in orthokeratology, overnight wear is intentional. For scleral lens wearers, additional teaching should include handling hygiene, use of appropriate preservative-free filling solution, plunger care, case replacement, and prompt reporting of fogging, redness, or discomfort that differs from baseline.

Multipurpose solutions (MPS) are convenient and widely used, but their safety depends on correct rub-and-rinse technique, fresh solution at every use, and meticulous case care. MPS preservatives, including polyhexamethylene biguanide, polyquaternium-1, and myristamidopropyl dimethylamine, can interact with lens materials and the ocular surface.¹² Reported adverse effects include epithelial disruption, solution-induced corneal staining, discomfort, toxic or allergic conjunctival reactions, and increased inflammatory events in susceptible patients.^10-23 These reactions are clinically relevant because symptoms may be misattributed to dry eye disease, lens fit, or end-of-day fatigue rather than to a lens-solution interaction. Experimental data suggest that some MPS-treated lenses may increase P aeruginosa internalization and disrupt mucin-barrier protection, whereas findings from clinical studies have linked certain solution-lens combinations to corneal staining and epithelial permeability.^13-15 When recurrent staining, limbal redness, papillary response, or unexplained discomfort occurs, clinicians should review the exact solution, lens material, rubbing technique, storage habits, and replacement schedule rather than simply refitting the lens.

Hydrogen peroxide systems avoid many preservative-related issues and may be useful for reusable lens wearers with recurrent staining, discomfort, inflammatory events, or suspected solution sensitivity.^17,20,22 These systems may also be helpful for patients with heavy deposit formation or those who require longer daily wearing time and struggle with end-of-day irritation. Their benefit depends on careful patient instruction, because incomplete neutralization can cause chemical injury. Patients should understand that peroxide solution must be used only with the manufacturer’s neutralizing case, must never be placed directly in the eye, and generally requires the full labeled neutralization time before lens insertion. Regardless of system, patients should never reuse or top off solution, should avoid water exposure, and should replace cases regularly. The care system should be treated as part of the prescription, not as an interchangeable retail product, because solution changes can alter comfort, staining, and inflammatory risk.

Higher-risk populations

Adolescents and young adults, particularly those aged 15 to 24 years, have the highest risk of contact lens–related microbial keratitis and corneal inflammatory events.^4,8,9 This group may have variable sleep schedules, sports participation, travel, cosmetic lens interest, and lower perceived vulnerability, making anticipatory guidance essential. Additional higher-risk groups include cosmetic lens users who obtain lenses without professional fitting, athletes and swimmers tempted to expose lenses to water, immunocompromised patients, patients who delay care after symptom onset, and specialty lens wearers with more complex regimens.^6,9 Patients using cosmetic contact lenses should be reminded that noncorrective lenses are still medical devices and require proper fitting, prescription, hygiene instruction, and follow-up. Patients who travel should be advised to carry backup glasses, extra lenses, an appropriate solution, and a clean case and to remove their lenses immediately if symptoms develop while away from home.

Pediatric contact lens safety data are generally reassuring when children are carefully selected and supervised. Microbial keratitis incidence in children 12 years or younger is low and comparable to adult daily-wear rates, and individuals aged 8 to 15 years have a lower risk of corneal infiltrative events than older teenagers and young adults.^9,17 Success depends on maturity, parent involvement, clear instructions, and immediate discontinuation of wear with pain, redness, photophobia, discharge, or changes in vision. Pediatric candidates should demonstrate reliable handwashing, lens application, and removal skills; a willingness to follow replacement schedules; and the ability to verbalize when something feels wrong. Parents should understand that they are not simply supervising vision correction; they are helping manage a medical device. When pediatric microbial keratitis occurs, P aeruginosa remains a common isolate.^1,23

Clinical prevention strategies

Prevention requires brief, repeated, specific counseling at fitting visits; annual examinations; dispensing appointments; and problem-focused encounters. Clinicians should use simple, memorable rules: wash and dry hands before handling lenses; do not sleep in lenses unless specifically prescribed; keep lenses and cases away from all water; rub and rinse reusable lenses with fresh disinfecting solution; never top off solution; clean, air-dry, and replace cases regularly; follow the prescribed replacement schedule; and stop lens wear immediately for redness, pain, photophobia, discharge, or vision change.⁹ Counseling is most effective when it is behavior specific. Instead of asking whether patients “take good care” of their lenses, clinicians can ask whether they ever nap in lenses, shower in lenses, swim in lenses, reuse solution, stretch replacement schedules, or store lenses in anything other than approved disinfecting solution. Teach-back methods, written instructions, and team-based reinforcement can improve retention and help close the gap between what clinicians believe they communicated and what patients recall.⁹

Contact lens safety ultimately depends on matching lens modality and care system to patient behavior, ocular surface status, age, risk tolerance, and ability to adhere. Daily disposables should be considered for patients with poor adherence, frequent travel, high-risk hygiene behaviors, or solution sensitivity. Hydrogen peroxide systems may be preferred for selected reusable lens wearers with recurrent staining, discomfort, or inflammatory events. Documentation should include the prescribed lens, replacement schedule, wearing schedule, approved care system, water-avoidance counseling, and emergency instructions. This creates consistency across the care team and reinforces that lens wear is a clinical treatment plan rather than a consumer purchase. For every modality, urgent symptoms must be treated as potentially infectious until proven otherwise, and patients should be instructed to present with lenses, cases, and disinfection solutions when possible to support diagnosis and counseling.

Conclusion

Contact lens wear remains safe for most patients when lenses are prescribed appropriately and used as directed. The greatest threats are preventable: overnight wear, water exposure, poor hygiene, delayed care, inconsistent replacement, and inappropriate solution use. Optometrists reduce avoidable vision loss by prescribing the appropriate contact lens modality, providing repeated safety education, carefully monitoring higher-risk patients, and promptly managing early warning symptoms. A practical safety culture begins with the message that contact lenses are convenient, but they require the same respect as any medical device placed on the ocular surface. When clinicians reinforce this message consistently, patients are more likely to recognize risky shortcuts, discontinue lens wear early, and seek care before complications become threatening to vision.

References

1. Durand ML, Barshak MB, Sobrin L. Eye infections. N Engl J Med. 2023;389(25):2363-2375. doi:10.1056/NEJMra2216081

2. Cope JR, Collier SA, Srinivasan K, et al. Contact lens–related corneal infections — United States, 2005-2015. MMWR Morb Mortal Wkly Rep. 2016;65(32):817-820. doi:10.15585/mmwr.mm6532a2

3. Cope JR, Collier SA, Rao MM, et al. Contact lens wearer demographics and risk behaviors — United States, 2014. MMWR Morb Mortal Wkly Rep. 2015;64(32):865-870. doi:10.15585/mmwr.mm6432a2

4. Cope JR, Collier SA, Nethercut H, Jones JM, Yates K, Yoder JS. Risk behaviors for contact lens-related eye infections among adults and adolescents — United States, 2016. MMWR Morb Mortal Wkly Rep. 2017;66(32):841-845. doi:10.15585/mmwr.mm6632a2

5. Toumasis P, Tsantes AG, Tsiogka A, Samonis G, Vrioni G. From clinical suspicion to diagnosis: a review of diagnostic approaches and challenges in fungal keratitis. J Clin Med. 2024;13(1):286. doi:10.3390/jcm13010286

6. Sharma N, Bagga B, Singhal D, et al. Fungal keratitis: a review of clinical presentations, treatment strategies and outcomes. Ocul Surf. 2022;24:22-30. doi:10.1016/j.jtos.2021.12.001

7. Rhee M, Ahmad S, Amescua G, et al. Bacterial Keratitis Preferred Practice Pattern. Ophthalmology. 2024;131(4):87-133.

8. Sauer A, Meyer N, Bourcier T; French Study Group for Contact Lens–Related Microbial Keratitis. Risk factors for contact lens-related microbial keratitis. Eye Contact Lens. 2016;42(3):158-162. doi:10.1097/ICL.0000000000000180

9. Konne NM, Collier SA, Spangler J, Cope JR. Healthy contact lens behaviors communicated by eye care providers and recalled by patients — United States, 2018. MMWR Morb Mortal Wkly Rep. 2019;68(32):693-697. doi:10.15585/mmwr.mm6832a2

10. Stein RM, Clinch TE, Cohen EJ, Genvert GI, Arentsen JJ, Laibson PR. Infected vs sterile corneal infiltrates in contact lens wearers. Am J Ophthalmol. 1988;105(6):632-636. doi:10.1016/0002-9394(88)90056-6

11. Lazon de la Jara P, Papas E, Diec J, Naduvilath T, Willcox MDP, Holden BA. Effect of lens care systems on the clinical performance of a contact lens. Optom Vis Sci. 2013;90(4):344-350. doi:10.1097/OPX.0b013e318288e10c

12. Posch LC, Zhu M, Robertson DM. Multipurpose care solution-induced corneal surface disruption and Pseudomonas aeruginosa internalization in the rabbit corneal epithelium. Invest Ophthalmol Vis Sci. 2014;55(7):4229-4237. doi:10.1167/iovs.14-14513

13. Dutot M, Paillet H, Chaumeil C, Warnet JM, Rat P. Severe ocular infections with contact lens: role of multipurpose solutions. Eye (Lond). 2009;23(2):470-476. doi:10.1038/eye.2008.131

14. Gordon GM, Moradshahi N, Jeong S, Lane C, Fini ME. A novel mechanism of increased infections in contact lens wearers. Invest Ophthalmol Vis Sci. 2011;52(12):9188-9194. doi:10.1167/iovs.11-7658

15. Kitamata-Wong B, Yuen T, Li W, Svitova T, Zhou Y, Lin MC. Effects of lens-care solutions on hydrogel lens performance. Optom Vis Sci. 2017;94(11):1036-1046. doi:10.1097/OPX.0000000000001125

16. Berntsen DA, Hickson-Curran SB, Jones LW, et al; Performance of Contact Lens Solutions Study Group. Subjective comfort and physiology with modern contact lens care products. Optom Vis Sci. 2016;93(8):809-819. doi:10.1097/OPX.0000000000000901

17. Chalmers RL, Wagner H, Mitchell GL, et al. Age and other risk factors for corneal infiltrative events and inflammatory events in young soft contact lens wearers from the Contact Lens Assessment in Youth (CLAY) study. Invest Ophthalmol Vis Sci. 2011;52(9):6690-6696. doi:10.1167/iovs.10-7018

18. Dutot M, Warnet JM, Baudouin C, Rat P. Cytotoxicity of contact lens multipurpose solutions: Role of oxidative stress, mitochondrial activity and P2X7 cell death receptor activation. Eur J Pharm Sci. 2008;33(2):138-145. doi:10.1016/j.ejps.2007.10.006

19. Debbasch C, Brignole F, Pisella PJ, Warnet JM, Rat P, Baudouin C. Quaternary ammoniums and other preservatives’ contribution in oxidative stress and apoptosis on Chang conjunctival cells. Invest Ophthalmol Vis Sci. 2001;42(3):642-652.

20. Tichenor AA, Cofield SS, Gann D, et al. Frequency of contact lens complications between contact lens wearers using multipurpose solutions versus hydrogen peroxide in the United States and Canada. Eye Contact Lens. 2021;47(5):277-282. doi:10.1097/ICL.0000000000000761

21. Mondino BJ, Salamon SM, Zaidman GW. Allergic and toxic reactions of soft contact lens wearers. Surv Ophthalmol. 1982;26(6):337-344. doi:10.1016/0039-6257(82)90126-6

22. Nichols JJ, Chalmers RL, Dumbleton K, et al. The case for hydrogen peroxide contact lens care solutions: a review. Eye Contact Lens. 2019;45(2):69-82. doi:10.1097/ICL.0000000000000542

23. Miller JM, Binnicker MJ, Campbell S, et al. Guide to utilization of the microbiology laboratory for diagnosis of infectious diseases: 2024 update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Clin Infect Dis. 2024;ciae104. doi:10.1093/cid/ciae104