20 Follow-Up Care Practice Questions & Answers

1. 1. A soft lens wearer returns complaining that vision is blurred and variable but clears for an instant right after each blink. At the slit lamp the lens barely moves on blinking or in up-gaze, and a ring of conjunctival indentation is visible after the lens is removed. What does this describe?

   • A.A lens fitted too steep and too tight for the eye✓ Answer
   • B.A lens coated with a heavy film of protein
   • C.A lens fitted too flat and too loose for the eye
   • D.A lens that was inserted inside out on the eye

   Restricted movement, conjunctival drag and an indentation ring after removal are the classic signs of a steep, tight soft lens: the lens vaults the cornea, tear exchange is poor, so vision is variable and clears only for the moment the blink reshapes the tear film. A flat, loose lens instead is uncomfortable from the first minutes, moves excessively, and gives vision that improves while staring between blinks.

   Source: In-Contact (Contamac), Chapter 10, Fitting Soft Contact Lenses — assessment of a steep (tight) versus flat (loose) soft lens fitReport a problem with this question

2. 2. At a follow-up visit a soft lens decentres inferiorly, moves excessively with every blink and shows edge stand-off at the lower limbus. Which single parameter change is the first and most effective way to tighten this fit?

   • A.Order the same design in a higher water content
   • B.Order the same lens in a smaller overall diameter
   • C.Order the same lens in a larger overall diameter✓ Answer
   • D.Order the same design with a thinner centre thickness

   Fit is governed by sagittal depth: a larger overall diameter (or a steeper base curve) increases sag and tightens the lens, while a smaller diameter or a flatter base curve loosens it. For soft lenses diameter changes the fit far more predictably than base curve — roughly 0.50 mm of diameter is equivalent to 0.20 mm of base curve — so diameter is changed first. Higher water content gives a more flexible lens and loosens the fit further.

   Source: In-Contact (Contamac), Chapter 10 — sagittal depth: relationship of diameter and base curve to soft lens fitReport a problem with this question

3. 3. A rigid gas permeable lens shows a broad central pool of fluorescein with a trapped bubble, bearing in the mid-periphery, a very narrow band of edge clearance and sluggish movement on blinking. Which statement describes the fit and the over-refraction you should expect?

   • A.Too flat; over-refraction reads more minus than expected
   • B.Too steep; over-refraction reads more minus than expected✓ Answer
   • C.Too steep; over-refraction reads more plus than expected
   • D.Too flat; over-refraction reads more plus than expected

   Central pooling with trapped bubbles, mid-peripheral bearing, minimal edge clearance and poor movement all define a steep fit. A steep lens traps a thicker tear layer centrally, which acts as a plus-powered tear lens; the over-refraction must neutralise that plus and therefore reads more minus than expected. This is the basis of SAM — Steeper Add Minus. A flat fit creates a minus tear lens and a more plus over-refraction.

   Source: In-Contact (Contamac), Chapter 10 — rigid lens fluorescein patterns and tear lens power (SAM/FAP)Report a problem with this question

4. 4. A −3.00 D rigid diagnostic lens gives a clear over-refraction of −0.50 D, but the fit is judged too flat, so the same lens is ordered with the base curve steepened by 0.10 mm. Taking 0.05 mm of base curve as equal to 0.25 D of tear lens power, what power should be ordered?

   • A.−3.50 D
   • B.−4.00 D✓ Answer
   • C.−4.50 D
   • D.−3.00 D

   The diagnostic power combined algebraically with the over-refraction gives −3.50 D at the original base curve. Steepening the base curve by 0.10 mm adds 0.50 D of plus tear lens power, which must be neutralised by adding an equal amount of minus to the lens: −3.50 + (−0.50) = −4.00 D. This is SAM — Steeper Add Minus; flattening instead would require adding plus.

   Source: In-Contact (Contamac), Chapter 10 — tear lens power and base curve/power compensation (SAM/FAP)Report a problem with this question

5. 5. A rigid lens wearer with an incomplete blink shows triangular areas of punctate stain on the nasal and temporal cornea just outside the lens edge. Which explanation and first corrective step fit this finding?

   • A.The edge holds the lid off the cornea, so increase diameter and reduce edge lift✓ Answer
   • B.The care solution is toxic to the epithelium, so switch to a peroxide care system
   • C.The lens is binding centrally to the cornea, so reduce diameter and add edge lift
   • D.The lens front surface is deposited, so polish it and add an enzymatic cleaner

   This is 3 and 9 o'clock staining, the hallmark of rigid lens wear. The lens edge lifts the lid away from the cornea, so the exposed nasal and temporal zones are never properly re-wetted by the blink; excessive edge clearance, a small or low-riding lens and an incomplete blink all contribute. Increasing diameter and reducing edge clearance restores lid-driven wetting. Untreated, the dried zone can progress to a dellen and eventually to vascularised limbal keratitis.

   Source: In-Contact (Contamac), Chapter 16, Complications of Contact Lens Wear — 3 and 9 o'clock peripheral corneal stainingReport a problem with this question

6. 6. A patient who has worn rigid lenses for years, with a long history of untreated 3 and 9 o'clock staining, now has a raised whitish mass with blood vessels growing into it at the temporal limbus. What is this?

   • A.Contact lens peripheral ulcer (CLPU)
   • B.Vascularised limbal keratitis (VLK)✓ Answer
   • C.Contact lens acute red eye (CLARE)
   • D.Superior epithelial arcuate lesion (SEAL)

   Vascularised limbal keratitis is the end stage of chronic 3 and 9 o'clock staining in rigid lens wear: months to years of repeated peripheral drying and mechanical irritation produce an elevated, vascularised hyperplastic mass at the 3 or 9 o'clock limbus. SEAL is an asymptomatic superior arcuate epithelial split, CLARE an acute inflammatory reaction after overnight wear, and CLPU a small sterile peripheral ulcer.

   Source: In-Contact (Contamac), Chapter 16 — vascularised limbal keratitis as a sequel of chronic 3 and 9 o'clock stainingReport a problem with this question

7. 7. A silicone hydrogel wearer has no symptoms at all, but a thin arc-shaped full-thickness epithelial split is found a short distance inside the superior limbus, under the upper lid. What is the mechanism, and which change is appropriate?

   • A.Mechanical pressure from the upper lid on a stiff lens; refit to a softer material✓ Answer
   • B.Chronic hypoxia beneath a thick lens; refit into a more oxygen transmissible material
   • C.Exotoxin release from bacterial colonisation; stop wear and refer for antibiotic therapy
   • D.Preservative hypersensitivity from the care system; move to preservative-free solutions

   A superior epithelial arcuate lesion (SEAL) is mechanical: the upper lid presses a stiff, high-modulus silicone hydrogel lens against the superior cornea and splits the epithelium in an arc a few millimetres inside the limbus. It is characteristically asymptomatic and found on routine examination. Because the cause is lens modulus and edge design rather than oxygen, increasing oxygen transmissibility does not help; refitting into a lower-modulus material or a different edge design does.

   Source: In-Contact (Contamac), Chapter 16 — superior epithelial arcuate lesion (SEAL) and lens modulusReport a problem with this question

8. 8. A wearer of thin, high-water-content hydrogel lenses complains of dryness and irritation late in the day. An arc of punctate stain runs across the inferior cornea between roughly the 4 and 8 o'clock positions. What is the most likely cause?

   • A.Mechanical abrasion from the upper lid pressing on the lens
   • B.Incomplete blinking that leaves the lens edge bridging the cornea
   • C.Trapped air bubbles indenting the epithelium beneath the lens
   • D.Dehydration of the lens with an inadequate post-lens tear film✓ Answer

   This is inferior arcuate or 'smile' staining. A thin, high-water hydrogel lens dehydrates through the day, the post-lens tear film thins and the lens adheres over the lower cornea, drying the epithelium in an inferior arc. Because the cause is material behaviour rather than curvature, the correct response is a lower-water or silicone hydrogel material and more frequent replacement, not a base-curve change.

   Source: In-Contact (Contamac), Chapter 16 — inferior arcuate ('smile') staining and lens dehydrationReport a problem with this question

9. 9. You remove a high-riding rigid lens, instil fluorescein and see a cluster of small round pools of dye over the central cornea. The patient has no pain, and the appearance has cleared within the hour. What is happening and what should be changed?

   • A.Dye is staining epithelium killed by a preservative; change the solution
   • B.Dye is staining an abrasion from a foreign body; inspect the lens edge
   • C.Dye is pooling in indentations left by trapped bubbles; flatten the base curve✓ Answer
   • D.Dye is pooling over stromal infiltrates; stop wear and refer today

   This is dimple veiling. Air bubbles trapped under a steep or high-riding rigid lens press transient depressions into the epithelium; fluorescein pools in those depressions but no epithelial cells are lost, which is why there is no pain and the appearance resolves spontaneously. True staining means tissue damage. Flattening the base curve stops bubbles being trapped under the lens.

   Source: In-Contact (Contamac), Chapter 16 — dimple veiling: fluorescein pooling versus true corneal stainingReport a problem with this question

10. 10. An extended-wear patient reports hazy vision and rainbow halos around lights on waking. Which slit lamp finding indicates the greater degree of corneal swelling?

    • A.Fine limbal vessels reaching into the clear cornea
    • B.Punctate staining scattered across the epithelium
    • C.Fine vertical striae in the posterior stroma
    • D.Folds in the posterior stroma and Descemet's✓ Answer

    Hypoxic corneal oedema produces a graded sequence of signs: fine vertical striae appear first, at a modest degree of stromal swelling, whereas folds in the posterior stroma and Descemet's membrane appear only when swelling is substantially greater. Folds therefore indicate the more severe oedema. The hazy vision with rainbow halos is central epithelial oedema (Sattler's veil), and management is a higher oxygen transmissibility, thinner lens and a move away from overnight wear.

    Source: In-Contact (Contamac), Chapter 16 — corneal oedema: striae and folds as indicators of the degree of swellingReport a problem with this question

11. 11. A long-term extended-wear hydrogel patient has fine superficial vessels extending from the limbus into the clear cornea. Which statement about this finding is correct?

    • A.The vessels are a normal adaptive response to any lens wear
    • B.The vessels regress completely within a few days of stopping wear
    • C.The vessels may empty and persist as ghost vessels after a refit✓ Answer
    • D.The vessels indicate an active bacterial infection of the cornea

    Corneal neovascularisation is driven chiefly by chronic hypoxia, and unlike oedema it is not truly reversible: when the oxygen supply improves the vessels empty of blood and remain as ghost vessels rather than disappearing. That is why management is preventive — higher oxygen transmissibility, a thinner or less tight lens, and a move from extended wear to daily wear or daily disposables.

    Source: In-Contact (Contamac), Chapter 16 — corneal neovascularisation and ghost vesselsReport a problem with this question

12. 12. A patient refitted from PMMA into rigid gas permeable lenses says his spectacles are blurred for hours after he takes the lenses out, and the keratometry mires are distorted. What is the correct plan?

    • A.Discontinue lens wear and re-measure K readings once they stabilise✓ Answer
    • B.Polish the front surface of both lenses and review the patient in a week
    • C.Change to a preservative-free care system and add rewetting drops
    • D.Order a flatter base curve immediately from the distorted K readings

    Spectacle blur after lens removal with distorted mires is corneal moulding, or warpage, classically caused by PMMA and low-oxygen rigid lenses. Any lens ordered from warped keratometry will be wrong once the cornea recovers its true shape, so lens wear is stopped and the K readings repeated at intervals until they are stable and repeatable before a new lens is designed.

    Source: In-Contact (Contamac), Chapter 16 — corneal moulding/warpage and spectacle blurReport a problem with this question

13. 13. A patient who sleeps in lenses wakes with mild discomfort in one eye. There is a small, round, focal yellowish-white infiltrate in the peripheral cornea with overlying epithelial loss that stains, but there is no discharge and no anterior chamber reaction. Which condition and mechanism does this describe?

    • A.Contact lens peripheral ulcer, a sterile reaction to gram-positive exotoxin✓ Answer
    • B.Microbial keratitis, an active infection needing same-day referral
    • C.Contact lens acute red eye, a sterile reaction to gram-negative toxin
    • D.Superior epithelial arcuate lesion, a mechanical split under the lid

    A contact lens peripheral ulcer is a sterile inflammatory response to exotoxins from gram-positive bacteria, chiefly Staphylococcus, colonising the lens surface. It appears as a small round peripheral infiltrate with full-thickness epithelial loss, is self-limiting over days and heals leaving a small scar. The absence of purulent discharge, of an anterior chamber reaction and of pain out of proportion to the signs distinguishes it from microbial keratitis.

    Source: In-Contact (Contamac), Chapter 16 — contact lens peripheral ulcer (CLPU) as a sterile infiltrative eventReport a problem with this question

14. 14. A hydrogel extended-wear patient is woken in the early hours by a painful red eye. There is intense circumlimbal injection, tearing and photophobia, with diffuse and focal infiltrates in the periphery reaching the limbus, and the epithelium does not stain. Which condition is this?

    • A.Vascularised limbal keratitis (VLK)
    • B.Contact lens papillary conjunctivitis (CLPC)
    • C.Contact lens acute red eye (CLARE)✓ Answer
    • D.Contact lens peripheral ulcer (CLPU)

    Contact lens acute red eye is an acute sterile inflammatory reaction that wakes the patient during or after overnight wear of a tightly adhering hydrogel lens. Endotoxin from gram-negative bacteria trapped behind the lens in the closed-eye environment drives diffuse and focal infiltrates that extend right to the limbus with the epithelium intact. It settles over days without scarring once wear stops, and refitting into higher oxygen transmissibility or daily disposable lenses prevents recurrence.

    Source: In-Contact (Contamac), Chapter 16 — contact lens acute red eye (CLARE)Report a problem with this question

15. 15. A patient who sleeps in lenses reports severe pain out of proportion to the appearance of the eye, thick discharge, and a dense infiltrate with an overlying epithelial defect and a small hypopyon. What is the correct action?

    • A.Remove the lens and refit with a daily disposable next week
    • B.Continue wear on a reduced schedule and review in one week
    • C.Reduce wearing time and switch to a preservative-free solution
    • D.Remove the lens and arrange same-day care with the prescriber✓ Answer

    Pain out of proportion to the signs, purulent discharge, an epithelial defect overlying a large infiltrate and an anterior chamber reaction are the hallmarks of microbial keratitis, a sight-threatening infection whose risk rises sharply with overnight wear. Lens wear stops immediately and the patient is seen by the prescribing practitioner the same day; a parameter, material or care-system change is never the response to a suspected corneal infection.

    Source: In-Contact (Contamac), Chapter 16 — microbial keratitis: recognition and urgent referralReport a problem with this question

16. 16. A lens wearer has pain far out of proportion to the visible signs, and a ring-shaped infiltrate is developing. Which item in the history most raises the suspicion of Acanthamoeba keratitis?

    • A.Rubbing the lenses with a surfactant cleaner before storing them
    • B.Rinsing the case with tap water and wearing lenses in the shower✓ Answer
    • C.Stretching a monthly replacement lens to six weeks of wear time
    • D.Sleeping overnight in a low-oxygen hydrogel lens for several months

    Acanthamoeba is a free-living organism of domestic water supplies, so tap water contact with lenses or storage cases, showering, swimming or hot tub use while wearing lenses, and homemade saline are the classic risk factors. Pain grossly out of proportion to the clinical signs, followed later by a ring infiltrate and radial keratoneuritis, is the characteristic presentation, and the preventive rule taught to every wearer is that lenses and cases must never touch tap water.

    Source: In-Contact (Contamac), Chapter 16 — Acanthamoeba keratitis: water exposure and risk factorsReport a problem with this question

17. 17. A monthly replacement wearer describes itching that is worst as the lenses come out, stringy mucus and increasing lens awareness with excessive lens movement. Everting the upper lid shows large papillae on the tarsal conjunctiva. Once wear has been stopped until the eye is quiet, which change addresses the cause most directly?

    • A.Move to a thicker lens design to resist front surface deposition
    • B.Move to a steeper base curve to reduce the excessive lens movement
    • C.Move to a higher water content to improve end-of-day comfort
    • D.Move to a much more frequent replacement, ideally daily disposables✓ Answer

    Giant papillary conjunctivitis is a combined mechanical and hypersensitivity reaction directed at deposits accumulating on the lens surface, and it is far commoner with monthly or longer replacement than with frequent replacement. Removing the deposit load — daily disposables or much more frequent replacement, with a hydrogen peroxide or preservative-free care system and protein removal — treats the cause. Changing curvature or thickness does not address the deposits.

    Source: In-Contact (Contamac), Chapter 16 — giant (contact lens) papillary conjunctivitis and replacement frequencyReport a problem with this question

18. 18. Two days after being changed to a different multipurpose solution, a patient has burning on insertion, red eyes and diffuse punctate staining spread evenly over the whole cornea. Which change addresses the cause?

    • A.Change to a thinner lens of the same material, keeping the solution
    • B.Change to a lens with a steeper base curve to improve the centration
    • C.Change to a hydrogen peroxide system, fully neutralised each time✓ Answer
    • D.Change to a saline rinse and store the lenses in saline overnight

    Diffuse punctate staining spread over the entire cornea with injection and burning, appearing soon after a change of solution, is the signature of preservative toxicity or hypersensitivity. Moving to a preservative-free system — hydrogen peroxide, fully neutralised by its catalytic disc or catalase tablet before the lens goes on the eye — removes the offending agent. Unneutralised peroxide causes immediate chemical injury, and saline neither disinfects nor stores lenses safely.

    Source: In-Contact (Contamac), Chapter 16 — solution toxicity and preservative hypersensitivity; hydrogen peroxide neutralisationReport a problem with this question

19. 19. At a follow-up visit you want to instil dye to assess the fit and the tear film while the hydrogel lens stays on the eye. Which statement governs this?

    • A.Only high-molecular-weight fluorescein should be used with the lens in place✓ Answer
    • B.Any dye may be used provided the lens is rinsed thoroughly with saline after
    • C.Standard sodium fluorescein is safe because hydrogel material repels the dye
    • D.Dye should never be instilled with a lens on the eye under any circumstances

    Standard sodium fluorescein is a small molecule that is absorbed by hydrogel material and permanently stains it, so only high-molecular-weight fluorescein (fluorexon) is instilled with a soft lens in situ. Once the lens is off the eye, standard fluorescein is used normally, viewed with cobalt blue illumination and a yellow barrier filter to enhance contrast when assessing the ocular surface.

    Source: In-Contact (Contamac), Chapter 10 — use of high-molecular-weight fluorescein (fluorexon) with hydrogel lenses in situReport a problem with this question

20. 20. A patient is comfortable with one rigid lens but reports a persistent edge sensation with the other, whose edge is verified as thick and blunt. What is the appropriate in-office handling, and what limit applies?

    • A.Steepen the base curve on the bench; this restores the original edge profile
    • B.Taper and polish the rigid lens edge; a hydrogel lens could not be modified✓ Answer
    • C.Taper and polish either lens edge; hydrogel lenses respond to the same tools
    • D.Increase the diameter on the bench; this reduces the awareness at the edge

    Only rigid lenses can be modified in the office: an anterior bevel tool tapers a thick edge and polishing smooths it, which is the standard remedy for edge awareness, whereas hydrogel material cannot be worked on a modification unit. Remember that essentially every modification flattens the fit slightly, that diameter can only be reduced and never increased, and that working a surface-treated lens destroys the treatment — so base curve, power, diameter and edge are re-verified and the change recorded.

    Source: Contact lens modification and verification — in-office edge tapering and polishing of rigid lenses (Contact Lens Spectrum, in-office RGP modification)Report a problem with this question

Practice questions based on the ABO-NCLE Contact Lens Registry Exam content domains and standard contact lens references, together with the FTC Contact Lens Rule and FDA device classification. This site is not affiliated with or endorsed by ABO-NCLE. Contact lens fitting is regulated state by state — scope of practice, supervision and licensure requirements vary, so confirm your own state's rules and work under the prescriber's direction. Verify current exam requirements with ABO-NCLE before testing. About the ABO-NCLE exams →