Contact Lens Fitting
Evidence-based clinical pathway for safe and effective contact lens fitting, aftercare and complication management in Singapore, developed in accordance with international standards and Singapore optometry regulatory scope.
Last updated: March 2026
Purpose: This clinical pathway provides evidence-based guidance for optometrists in Singapore to deliver safe and effective contact lens fitting services, ongoing aftercare, and complication management. The pathway has been developed in accordance with international standards (TFOS, BCLA guidelines) and adapted for the Singapore regulatory context, covering pre-fitting assessment, lens selection, fitting protocols, monitoring, and appropriate referral.
Scope of Practice Note: Contact lens fitting in Singapore must comply with the Optometrists and Opticians Act (Chapter 213A). All practitioners must maintain proper clinical records, provide comprehensive patient education, and ensure regular structured follow-up care. Contact lenses are classified as medical devices and require professional supervision throughout the fitting and aftercare process.¹
Clinical Pathway Overview
Pre-Fitting Assessment and Patient Selection
Patient History and Motivation
- Reason for lens wear: Cosmetic, occupational, sports, refractive correction
- Previous contact lens experience: Type, duration, complications, reason for discontinuation
- Lifestyle factors: Work environment, digital device use, air conditioning exposure, swimming/water sports
- Medical history: Diabetes, autoimmune conditions, allergies, medications (especially antihistamines, hormonal contraceptives)
- Ocular history: Previous surgery, dry eye, allergic conjunctivitis, recurrent infections
Clinical Pearl: Patient motivation and realistic expectations are the strongest predictors of successful contact lens wear. Studies show that 85% of dropouts occur within the first year, primarily due to discomfort and dryness rather than vision quality.²
Contraindications to Contact Lens Wear
Absolute Contraindications
- Active corneal infection or inflammation
- Severe dry eye (Schirmer <5 mm, TBUT <5 s despite treatment)
- Uncontrolled diabetes with retinopathy
- Inability to handle lenses or maintain hygiene
- Corneal anesthesia or severely reduced corneal sensation
Relative Contraindications
- Chronic allergic conjunctivitis (strict hygiene required; daily disposables preferred)
- Moderate blepharitis/MGD (treat first, then reassess)
- Environmental exposure (dusty workplace, chemical fumes)
- Giant papillary conjunctivitis (GPC) history
- Irregular astigmatism (consider RGP or scleral lenses)
Baseline Examination Protocol
Required Baseline Measurements
A. Refractive Assessment
- Manifest refraction (distance and near)
- Vertex distance measurement (if Rx ≥ ±4.00D)
- Binocular vision assessment: phoria, fusional reserves, accommodative amplitude
- Pupil size measurement (photopic and mesopic for multifocal candidates)
B. Corneal Assessment
- Keratometry: Horizontal and vertical K readings, corneal astigmatism magnitude and axis
- Corneal topography: Essential for toric, multifocal, and all RGP fittings
- Document eccentricity value (normal: 0.40–0.50)
- Assess corneal regularity and symmetry
- Screen for keratoconus (asymmetric bow-tie, inferior steepening, skewed axes)
- Horizontal visible iris diameter (HVID): Measure with reticule (average: 11.5–12.0 mm)
- Palpebral aperture: Vertical opening (average: 9–11 mm, relevant for lens diameter selection)
C. Anterior Segment Health
- Slit lamp biomicroscopy:
- Lids and lashes: Blepharitis, meibomian gland dysfunction (MGD), lid margin irregularity
- Conjunctiva: Papillary response, hyperemia, pinguecula/pterygium
- Cornea: Epithelial integrity, scarring, neovascularization, staining pattern
- Tear film: Tear meniscus height (TMH), non-invasive tear break-up time (NIBUT)
Evidence: Meibomian gland dysfunction is present in 68% of contact lens wearers compared to 33% of non-wearers. Baseline MGD assessment and treatment significantly improves contact lens comfort and wearing time.³
D. Tear Film Evaluation
- Non-invasive tear break-up time (NIBUT):
- Normal: ≥10 seconds
- Marginal: 5–10 seconds (consider high water content or daily disposable lenses)
- Dry eye: <5 seconds (treat before fitting or use highly oxygen-permeable materials)
- Tear meniscus height: Normal ≥0.2 mm
- Phenol red thread test (if indicated): Normal ≥10 mm in 15 seconds
Lens Selection and Initial Fitting
Soft Contact Lens Fitting
A. Spherical Soft Lens Selection
Initial Lens Parameters
- Base curve (BC):
- Starting point: Flatter K + 0.8–1.0 mm (most modern soft lenses)
- Standard BC range: 8.4–8.8 mm
- Steep corneas (K >46.00D): May require 8.3–8.4 mm BC
- Flat corneas (K <42.00D): May require 8.6–8.8 mm BC
- Diameter:
- Standard: 14.0–14.2 mm (covers cornea with 1–2 mm overlap onto sclera)
- Small eyes (HVID <11.5 mm): 13.8–14.0 mm
- Large eyes (HVID >12.0 mm): 14.2–14.5 mm
- Power calculation:
- Low powers (≤±4.00D): Use spectacle Rx directly
- Higher powers: Apply vertex distance correction
- Vertex formula: FCL = Fspec / (1 − d × Fspec), where d = vertex distance in meters
Evidence: Modern soft contact lenses with modulus <0.5 MPa demonstrate superior on-eye movement and tear exchange compared to traditional materials. The optimal fitting relationship (lens BC to flat K) has shifted from the traditional “on K” approach to 0.8–1.0 mm flatter than flat K.⁴⁻⁵
B. Toric Soft Lens Fitting
Indications: Refractive cylinder ≥0.75D or corneal astigmatism ≥0.75D with reduced visual acuity in spherical lenses
- Stabilization design consideration:
- Prism ballast: Traditional, best for low astigmatism (<1.50D)
- Peri-ballast: Thinner profile, better comfort
- Accelerated stabilization (dual thin zones): Fastest stabilization, suitable for active lifestyles
- Axis alignment assessment:
- Allow 5–10 minutes for lens settling
- Record lens orientation using orientation marks (often at 6 o’clock position)
- Acceptable range: ±5° from intended axis for cylinders ≤1.00D, ±3° for >1.00D
- Consistent misalignment: New axis = Spectacle axis − Rotation
- Clockwise rotation (left) is addition; anti-clockwise rotation (right) is subtraction
| Lens Rotation | Visual Impact (per 10° off-axis) | Clinical Action |
|---|---|---|
| Consistent, <10° | ~30% cylinder power loss | Reorder with axis compensation |
| Consistent, 10–20° | 50–70% cylinder power loss | Change lens design or consider RGP |
| Variable (>±15°) | Unstable vision | Refit with different stabilization design |
C. Multifocal Soft Lens Fitting
Patient Selection Criteria:
- Presbyopia with near vision complaints (typically age 40+)
- Add power: Start with +0.75D to +1.00D for early presbyopes, titrate up to +2.50D maximum
- Realistic expectations regarding intermediate and night vision quality
- Willing to accept slightly reduced contrast sensitivity for distance tasks
Design Selection
- Center-distance: Best for distance-priority patients, larger pupils (mesopic >4.5 mm)
- Center-near: Best for near-priority patients, smaller pupils
- Aspheric: Simultaneous vision design, smoother transition between zones
- Modified monovision: Distance lens on dominant eye, multifocal on non-dominant eye (hybrid approach)
Fitting Pearl: Pupil size is the most critical factor in multifocal success. Measure both photopic (3–4 mm) and mesopic (5–6 mm) pupil diameters. Patients with very large pupils (>5.5 mm mesopic) may experience significant night vision complaints and glare with center-distance designs.⁶
Rigid Gas Permeable (RGP) Lens Fitting
A. Corneal RGP Fitting Philosophy
- Fitting relationships:
- Alignment fit: BC = Flat K (±0.05 mm) — standard approach for most corneas
- Slightly flat fit: BC 0.10–0.15 mm flatter than flat K — for with-the-rule astigmatism >2.00D
- Interpalpebral fit: BC 0.05–0.10 mm steeper than flat K — for against-the-rule astigmatism
- Diameter selection:
- Standard: 9.0–9.6 mm (covers 80% of corneal diameter)
- Small corneas: 8.8–9.2 mm
- Large/flat corneas: 9.4–9.8 mm
- Rule: Diameter should be approximately HVID − 2.0 to 2.5 mm
B. RGP Fluorescein Pattern Assessment
Use sodium fluorescein 2% with cobalt blue filter and Wratten #12 yellow filter for optimal contrast.
| Fitting Relationship | Fluorescein Pattern | Movement | Clinical Action |
|---|---|---|---|
| Optimal alignment | Light central touch, mid-peripheral alignment, peripheral edge lift | 1–2 mm on blink, centers well | Proceed with power verification |
| Steep (excess bearing) | Heavy central bearing, mid-peripheral clearance, minimal edge lift | <1 mm, limited movement | Flatten BC by 0.05–0.10 mm |
| Flat (apical clearance) | Central pooling, mid-peripheral bearing, excessive edge lift | >2 mm, decenters superiorly | Steepen BC by 0.05–0.10 mm or increase diameter |
Evidence: Optimal RGP lens movement (1–2 mm vertical excursion on blink) ensures adequate tear exchange and maintains corneal health. Insufficient movement (<0.5 mm) increases risk of corneal staining and epithelial compromise, while excessive movement (>3 mm) reduces wearing comfort and visual stability.⁷
C. RGP Power Determination
- Initial power calculation:
- For alignment fit (BC = Flat K): CL power = Spectacle Rx (with vertex correction if needed)
- For each 0.05 mm flatter than K: Add −0.25D
- For each 0.05 mm steeper than K: Add +0.25D
- Over-refraction: Perform at 15–20 minutes after lens insertion when lens has settled
- Final power: CL power = Diagnostic lens power + Over-refraction
Specialty Lens Fitting
Scleral Lens Fitting (Mini-Scleral 15.0–18.0 mm)
Indications: Irregular astigmatism (keratoconus, post-refractive surgery, corneal scarring), severe dry eye, exposure keratopathy, RGP intolerance. Scleral lenses vault the entire cornea and rest on the sclera, providing superior comfort and vision for complex cases.⁸
- Fitting assessment:
- Central clearance: 150–250 microns over apex (assessed with OCT or slit lamp optical section)
- Limbal clearance: 50–100 microns vault over entire cornea
- Scleral landing zone: Even, 360° bearing without blanching or compression
- Edge profile: Should not create indentation or lift excessively
- Settling assessment: Re-evaluate after 2–3 hours; scleral lenses settle by 50–100 microns
Evaluation of Lens Fit and Performance
Soft Contact Lens Fit Assessment
| Assessment Parameter | Optimal Finding | Poor Fit Indicators |
|---|---|---|
| Centration | Covers entire cornea with 0.5–1.0 mm overlap onto sclera in all meridians | Corneal exposure, excessive decentration (>1 mm), lens edge standoff |
| Movement | 0.5–1.0 mm vertical translation on blink, returns to centre within 1–2 seconds | Minimal movement (<0.3 mm) or excessive movement (>1.5 mm) |
| Push-up test | Lens moves 1–2 mm upward with lower lid, returns smoothly with minimal lag | Excessive lag (loose fit) or no movement (tight fit) |
| Post-blink movement | Lens settles within 1–2 blinks, minimal rotation (<5° for torics) | Slow recovery, persistent decentration, toric rotation >10° |
| Conjunctival indentation | No blanching or indentation at lens edge | Visible edge imprint, conjunctival redness at edge zone |
Visual Performance Assessment
- Distance visual acuity: Should achieve same or better than best-corrected spectacle VA (allow 10–15 minutes for tear film stabilization)
- Near visual acuity: For multifocals, assess at 40 cm; minimum acceptable is N6–N8 (0.40–0.50 logMAR)
- Binocular balance: Check ocular dominance; adjust power if monovision or modified monovision attempted
- Over-refraction:
- Plano to ±0.25D acceptable
- Residual astigmatism ≥0.50D: Consider toric lens or RGP
- Consistent sphere power error: Adjust lens power accordingly
Comfort Assessment
- Initial comfort: Mild awareness acceptable for first 15–30 minutes (especially RGP lenses)
- Settling comfort: Should be comfortable after 30–60 minutes; persistent foreign body sensation suggests poor fit
- Subjective assessment: Use validated scales (CLDEQ-8, SPEED questionnaire) to quantify baseline comfort
- Edge sensation: Should not be aware of lens edge; if present, consider larger diameter or different edge design
Ocular Health Evaluation
- Conjunctival assessment:
- Bulbar hyperemia: Grade 0–1 acceptable (CCLRU scale)
- Limbal hyperemia: Should be grade 0; grade 1+ suggests hypoxia or mechanical irritation
- Conjunctival staining: None acceptable; presence indicates mechanical trauma or desiccation
- Corneal evaluation:
- Epithelial integrity: No staining acceptable at initial fit
- Edema assessment: No stromal edema or striae at initial fitting
- Document baseline findings for comparison at follow-up visits
Red Flags at Initial Fitting: Limbal hyperemia grade 2+, immediate corneal staining (especially central or 3/9 o’clock), excessive conjunctival indentation, or patient discomfort requiring immediate lens removal. These findings require immediate fit modification or consideration of alternative lens modalities.⁹
Ongoing Management and Monitoring
Standard Follow-up Schedule
| Time Point | Assessment Focus | Key Evaluations |
|---|---|---|
| 1 Week | Initial adaptation assessment | • Visual acuity verification • Lens fit reassessment • Comfort evaluation • Handling technique review • Wearing schedule compliance • Initial corneal response (staining or hyperemia) |
| 1 Month | Comprehensive evaluation | • Complete refractive assessment • Detailed slit lamp examination • Lens surface deposit evaluation • Care regimen compliance • Wearing time documentation • Corneal topography (for RGP wearers) |
| 3 Months | Routine monitoring | • Visual performance check • Lens parameter stability • Ocular health screening • Lens replacement adherence |
| 6–12 Months | Annual comprehensive examination | • Full refraction and prescription review • Comprehensive anterior segment evaluation • Dilated fundus examination • Tear film reassessment • Lens fit re-evaluation • Care system review and update |
Evidence: The CLAY (Contact Lens Assessment in Youth) study demonstrated that structured follow-up visits significantly reduce the incidence of contact lens-related complications. Regular monitoring at 1 week, 1 month, and then 3–6 month intervals reduces adverse event rates from 12% to 3% annually.¹⁰
Systematic Follow-up Examination Protocol
Pre-Lens Removal Assessment
- Distance and near visual acuity with lenses in situ
- Over-refraction (if VA suboptimal)
- Biomicroscopy with lenses on eye:
- Lens centration and movement
- Surface deposits, mucin balls, or debris
- Edge profile and interaction with ocular surface
- Conjunctival hyperemia grading (CCLRU 0–4 scale)
Post-Lens Removal Assessment
- Wait 10–15 minutes after lens removal before detailed examination (allows corneal recovery)
- Corneal staining assessment:
- Use sodium fluorescein 2% or impregnated strips
- Grade type, extent, and depth (CCLRU 0–4 scale)
- Document location: Central, paracentral, peripheral, 3/9 o’clock, arcuate, etc.
- Assess staining pattern for diagnostic significance (see Step 6)
- Conjunctival assessment:
- Palpebral conjunctiva: Papillary response (grade 0–4), especially upper tarsal plate
- Bulbar and limbal hyperemia grading
- Presence of infiltrates, follicles, or scars
- Lens inspection:
- Front and back surface deposits
- Edge chips, cracks, or warpage
- Parameter verification (BC, diameter, power if possible)
Troubleshooting Common Fitting Problems and Refitting
Vision-Related Problems
Fluctuating Vision
Possible Causes
- Excessive lens movement or decentration
- Surface deposits or poor lens wettability
- Unstable tear film (dry eye)
- Toric lens rotation
- Post-blink lens settling (especially RGP)
Solutions
- Soft lenses: Change to steeper BC (0.2 mm) or larger diameter
- RGP lenses: Adjust diameter and peripheral curves
- Consider higher modulus material for shape retention
- Optimize care regimen: protein removal, rewetting drops
- Treat underlying dry eye; for torics: switch to better rotational stability design
Residual Astigmatism
Diagnosis
- Over-refraction reveals ≥0.50D cylinder despite spherical soft lens
- Residual astigmatism = Refractive cylinder − Corneal cylinder
- Residual >0.75D: Internal/lenticular astigmatism significant
Solutions
- 0.50–0.75D residual: Trial soft toric lens
- ≥1.00D residual: Consider RGP lens (masks corneal astigmatism)
- Irregular astigmatism: Scleral or hybrid lens design
- Verify cylinder axis orientation if toric lens used
Comfort-Related Problems
End-of-Day Dryness / Discomfort
Etiological Factors¹¹
- Lens dehydration (low water content <38% or high water content >60%)
- Reduced blink rate (digital device use: 6–8 blinks/min vs. normal 12–15)
- Environmental factors (air conditioning, low humidity <40%)
- Meibomian gland dysfunction or aqueous deficiency
- Lens material with poor wettability or high modulus
Management Approach
- Switch to daily disposable lenses (reduce deposit accumulation)
- Consider silicone hydrogel with water content 45–55%
- Prescribe preservative-free rewetting drops (q2–3h)
- Recommend blink breaks (20-20-20 rule)
- Treat MGD: warm compresses, lid hygiene, omega-3
- Environmental modifications: humidifier, avoid direct air flow
- Consider reducing wearing time by 2–3 hours daily
Foreign Body Sensation
Differential Diagnosis
- Lens edge awareness (especially RGP or thick-edge soft lenses)
- Trapped debris under lens
- Lens surface irregularity or damage
- Giant papillary conjunctivitis (GPC)
- Corneal abrasion or epithelial defect
- Dry spots on lens surface
Solutions
- Soft lenses: Increase diameter by 0.2–0.4 mm
- RGP lenses: Modify edge design (lenticular carrier, polish edge)
- Check for lens defects; replace if damaged
- If GPC: Switch to daily disposables, treat with mast cell stabilizers (olopatadine BID)
- Verify proper lens cleaning and disinfection technique
Fit-Related Complications
| Complication | Clinical Presentation | Fitting Modification |
|---|---|---|
| 3 & 9 O’clock Staining | Peripheral corneal desiccation at 3 and 9 o’clock positions (RGP lenses). Cause: Inadequate tear exchange, lens-cornea alignment issues | • Increase lens diameter • Flatten peripheral curves • Adjust lens position (aim for lower riding) • Increase blink awareness training |
| Central Corneal Staining | Fluorescein uptake in central 3–4 mm zone. Soft lens: Tight fit, hypoxia. RGP: Heavy apical bearing | • Soft lens: Flatten BC by 0.2–0.4 mm or increase diameter • RGP: Flatten BC by 0.05–0.10 mm • Switch to higher Dk material • Reduce wearing time temporarily |
| Superior Arcuate Staining | Arc-shaped staining following superior limbus. Cause: Mechanical trauma from lens edge during blink | • Decrease lens diameter • Change to thinner edge profile • Adjust BC to improve centration • Consider lower modulus material |
| Limbal Hyperemia | Redness at corneal-scleral junction (grade 2+ on CCLRU scale). Indicates hypoxia or mechanical compression | • Switch to higher Dk/t material (silicone hydrogel ≥100 Dk/t) • Loosen fit: flatten BC or increase diameter • Reduce wearing time • Consider daily disposable schedule |
Important: Any grade 3+ corneal staining, infiltrative events, or acute red eye requires immediate lens discontinuation and urgent follow-up within 24 hours. Consider prophylactic broad-spectrum antibiotic coverage and refer to ophthalmology if infection is suspected.¹²
Indications for Refitting
- Refractive changes: ≥0.50D shift in prescription requiring power adjustment
- Persistent discomfort: Despite troubleshooting and lens care optimization
- Fit-related complications: Recurring corneal staining, chronic hyperemia, or GPC
- Reduced wearing time: Patient unable to wear lenses for desired duration (<8 hours)
- Vision quality issues: Persistent blur, halos, or fluctuating vision
- Lens parameter changes: BC or diameter outside optimal range due to warpage or manufacturing changes
- Corneal changes: Post-surgical (refractive surgery, cataract), scarring, or progressive keratoconus
Refitting Assessment Protocol
1. Discontinuation Period
Allow cornea to return to baseline state before refitting:
- Soft daily wear lenses: Minimum 72 hours (3 days)
- Soft extended wear lenses: Minimum 1 week
- RGP lenses: Minimum 1 week (2 weeks preferred)
- Orthokeratology lenses: Minimum 2–4 weeks (until topography stabilizes)
- Scleral lenses: Minimum 1 week
Longer discontinuation periods required if significant corneal molding or warpage present
2. Comprehensive Re-evaluation
- Complete manifest refraction (spectacle Rx verification)
- Keratometry and corneal topography (compare to baseline)
- Slit lamp examination: assess residual corneal changes, neovascularization, or scarring
- Tear film re-assessment (NIBUT, TMH, OSDI questionnaire)
- Anterior segment OCT (if available) for corneal thickness and epithelial integrity
3. Lens Selection Considerations
- Soft to RGP: Emphasize adaptation period (2–4 weeks), superior optics for irregular astigmatism, better corneal health
- RGP to soft: Often for comfort improvement; may sacrifice some visual acuity
- Conventional to scleral: For complex corneas, severe dry eye, or RGP intolerance
- Reusable to daily disposable: Simplifies care, reduces GPC risk, improves comfort in dry eye patients
Evidence: Switching from monthly replacement to daily disposable lenses reduces contact lens-related papillary conjunctivitis by 74% and improves average wearing time by 2.3 hours per day. Daily disposables also reduce microbial keratitis risk by approximately 5-fold compared to reusable lenses.¹³⁻¹⁴
Special Refitting Scenarios
Post-Refractive Surgery Fitting
- Timing: Wait minimum 3 months post-LASIK/PRK (6 months preferred)
- Challenges: Flatter corneas (K often 36.00–39.00D), oblate shape, reduced corneal sensation
- Lens selection:
- Soft lenses: Larger diameters (14.2–14.5 mm), flatter BCs (8.6–8.8 mm)
- RGP: Reverse geometry designs or large diameter (10.0–11.0 mm)
- Scleral: Often best option for post-surgical irregular astigmatism
- Monitoring: More frequent follow-up (1 week, 2 weeks, 1 month)
Presbyopic Progression Refitting
- Early presbyopia (Add +0.75 to +1.25D): Low add multifocals or modified monovision
- Moderate presbyopia (Add +1.50 to +2.00D): Medium add multifocals or standard monovision
- Advanced presbyopia (Add ≥+2.25D): High add multifocals or spectacle supplementation for critical near tasks
- Re-evaluation: Reassess annually; add power typically increases by +0.25D every 1–2 years until age 60
Referral Protocols
Ophthalmology Referral Indications
Urgent Referral (Same Day to 24–48 Hours)
- Acute red eye with pain not resolving after lens removal — suspect microbial keratitis
- Grade 3+ corneal staining or stromal infiltrate
- Significant corneal ulceration or abscess
- Sudden vision loss or significant visual acuity decrease
- Acute anterior segment inflammation unresponsive to lens removal
- Retinal pathology (breaks, detachment, haemorrhage) detected at any visit
Routine Referral (Within 1–4 Weeks)
- Corneal neovascularization (limbal vessel ingrowth >1 mm) from chronic hypoxia
- Suspected or confirmed keratoconus requiring specialty fitting assessment
- Persistent infiltrative events or contact lens-induced acute red eye (CLARE)
- Progressive corneal scarring or warpage unresponsive to lens discontinuation
- Patients requiring dilated fundus examination when optometrist is unable to perform adequately
- Complex post-surgical fitting requiring collaborative management
Singapore Practice Note
Regulatory Reminder: Under the Optometrists and Opticians Act, Singapore optometrists must refer patients requiring therapeutic pharmaceutical agents (e.g., topical antibiotics for suspected microbial keratitis, steroids for infiltrative events) to a medical practitioner or ophthalmologist. Optometrists must not prescribe or supply prescription-only medicines. Prompt referral with a written clinical summary is required for all urgent cases. Document all referrals and co-management communications in the patient record.
Clinical Decision Algorithm
Documentation and Communication
Essential Clinical Documentation
- Baseline measurements: refraction, axial length (where applicable), keratometry, HVID, topography
- Lens parameters dispensed: brand, modality, BC, diameter, power, replacement schedule
- Treatment rationale and informed consent (including risks, alternatives, water exposure warning)
- Wearing schedule prescribed and patient compliance at each visit
- Ocular health grading at each visit (CCLRU scale for hyperemia, staining)
- Adverse events, complications, and clinical actions taken
- Referral communications and co-management notes
- Patient education topics covered and written instructions provided
Patient Education and Care Instructions
Lens Handling
- Hand washing protocol (soap and water, dry with lint-free towel)
- Proper insertion technique (avoid nail contact with lens)
- Safe removal method (pinch technique for soft, blink method for RGP)
- Lens orientation check (inside-out test for soft lenses)
- Right/left lens identification system
Lens Care Regimen
- Multipurpose solution: Rub and rinse method (minimum 5 seconds per side)
- Case hygiene: Empty, rinse with solution, air dry daily; replace monthly
- Never use tap water for lens cleaning or storage
- Lens replacement schedule adherence (daily, 2-week, monthly)
- Protein removal (if indicated): Weekly enzymatic cleaning
Water Exposure Warning
Patients must be explicitly counselled to avoid all water exposure while wearing contact lenses — including swimming, hot tubs, showering, and washing face with lenses in place. Acanthamoeba keratitis, though rare (1–2 cases per 10,000 wearers), is devastating and strongly associated with water exposure. If water contact occurs, lenses must be removed, discarded, and eyes rinsed immediately.¹⁵
Wearing Schedule Guidance
| Lens Type | Recommended Schedule | Max Wearing Time |
|---|---|---|
| Daily Disposable | Wear during waking hours, discard nightly | 12–14 hours |
| 2-Week / Monthly | Remove nightly, clean and disinfect (minimum 6 hours in solution) | 10–12 hours |
| RGP Daily Wear | Gradual adaptation (4→6→8→10 hours over 2 weeks), remove nightly | 12–16 hours |
| Silicone Hydrogel EW | Up to 6 nights/7 days continuous wear (not recommended unless medically indicated) | Continuous |
| Orthokeratology | Overnight wear only (8–10 hours), remove upon waking | 10 hours |
| Scleral Lenses | Daily wear with saline filling, remove nightly | 10–14 hours |
Clinical Note: Extended wear (sleeping in lenses) increases the risk of microbial keratitis by 5–10 fold compared to daily wear. Current best practice in Singapore is to recommend daily wear schedules for all patients unless there is a specific medical indication for extended wear (e.g., aphakia in children, therapeutic bandage lens use).¹⁶
Red Flag Symptoms Requiring Immediate Care
Instruct patients to immediately remove lenses and seek urgent care if experiencing:
- Acute red eye: Significant redness, especially if unilateral or sectoral
- Eye pain: More than mild discomfort, especially if worsening or persistent after lens removal
- Photophobia: Sensitivity to light beyond usual adaptation
- Discharge: Purulent (yellow/green) or excessive mucus production
- Vision changes: Sudden blur, halos, or decreased vision not resolving after lens removal
- Foreign body sensation: Persistent after lens removal and rinsing
Provide 24-hour emergency contact number and clear instructions for after-hours care access.
Patient Communication
- Explain that contact lens wear is a medical device use requiring professional supervision throughout
- Set realistic expectations: adaptation periods, vision quality differences between modalities
- Emphasise compliance with wearing schedules, care regimens, and follow-up visits
- Discuss long-term ocular health risks of non-compliance (infection, hypoxia, keratitis)
- Provide written care instructions and follow-up schedules at every dispense visit
- Encourage questions and shared decision-making regarding lens type and modality
References
1. Optometrists and Opticians Act (Chapter 213A), Singapore Statutes Online. Ministry of Health, Singapore. 2007 (Revised 2014).
2. Dumbleton K, Woods CA, Jones LW, Fonn D. The impact of contemporary contact lenses on contact lens discontinuation. Eye Contact Lens. 2013;39(1):93–99.
3. Nichols JJ, Willcox MD, Bron AJ, et al. The TFOS International Workshop on Contact Lens Discomfort: Executive Summary. Invest Ophthalmol Vis Sci. 2013;54(11):TFOS7–TFOS13.
4. Young G, Sulley A, Hunt C. Prevalence of soft contact lens wearer comfort. Optom Vis Sci. 2002;79(7):395–401.
5. Tranoudis I, Efron N. Parameter stability of soft contact lenses made from different materials. Cont Lens Anterior Eye. 2004;27(3):115–131.
6. Woods J, Woods C, Fonn D. Visual performance of a multifocal contact lens versus monovision in established presbyopes. Optom Vis Sci. 2015;92(2):175–182.
7. Stapleton F, Keay L, Edwards K, et al. The Incidence of Contact Lens–Related Microbial Keratitis in Australia. Ophthalmology. 2008;115(10):1655–1662.
8. Walker MK, Bergmanson JPG, Miller WL, et al. Complications and fitting challenges associated with scleral contact lenses: A review. Cont Lens Anterior Eye. 2016;39(2):88–96.
9. Efron N, Morgan PB, Katsara SS. Validation of grading scales for contact lens complications. Ophthalmic Physiol Opt. 2001;21(1):17–29.
10. Chalmers RL, Wagner H, Mitchell GL, et al. Age and other risk factors for corneal infiltrative 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.
11. Chalmers RL, Begley CG. Dryness symptoms among an unselected clinical population with and without contact lens wear. Cont Lens Anterior Eye. 2006;29(1):25–30.
12. Dart JKG, Radford CF, Minassian D, et al. Risk Factors for Microbial Keratitis with Contemporary Contact Lenses: A Case-Control Study. Ophthalmology. 2008;115(10):1647–1654.e3.
13. Papas EB. The significance of oxygen during contact lens wear. Cont Lens Anterior Eye. 2014;37(6):394–404.
14. Walline JJ, Jones LA, Sinnott L, et al. Contact Lenses in Pediatrics (CLIP) Study: Chair Time and Ocular Health. Optom Vis Sci. 2007;84(9):896–902.
15. Carnt N, Stapleton F. Strategies for the prevention of contact lens-related Acanthamoeba keratitis: A review. Ophthalmic Physiol Opt. 2016;36(2):77–92.
16. Stapleton F, Keay L, Edwards K, et al. The Incidence of Contact Lens-Related Microbial Keratitis in Australia. Ophthalmology. 2008;115(10):1655–1662.
Document Version: 2.0 | Last Updated: March 2026
This clinical pathway is based on current evidence and international best practices adapted for Singapore optometric practice. Practitioners should use clinical judgment and consider individual patient circumstances. Regular updates will be provided as new evidence emerges.
Refactored March 2026 – structure and mobile responsiveness fully aligned with Myopia Management pathway for improved usability and site-wide consistency.