CCFP priority topic 83 of 105
Red Eye on the CCFP exam
9 key features, the mistakes that cost marks, and a practice question.
Checked by a Canadian family physician, MD, CCFP. Updated October 20, 2026.
What the exam tests
Key features
The CFPC’s 9 key features for Red Eye. Each one below has how the exam asks it, the common mistakes and the approach.
Practice question
Try one before you read
A real case from the bank, in the new short-menu format. Answer it first. Then read the key features.
Key feature 1 of 9
Check vision first
Measure how well each eye sees whenever a patient comes in with an eye problem.
CFPC skill Clinical reasoningPhase History, physical
On the exam
A man with a red, sore eye after a weekend of yard work. Expect a short menu (pick several from a list) of first steps.
Pick what to check first.
Common mistakes
Reaching for the dye or a drop before recording vision. Skipping acuity because he says he sees fine is wrong too.
Approach
- Test each eye on its own, with glasses or contact lenses on if worn. Write the result in the chart.
- No glasses at hand? Test through a pinhole. It corrects most focusing error.
- Use a wall chart where you can. At the bedside, use a near card, finger counting, hand movement or light.
- In a baby or toddler, watch whether each eye fixes on a face or toy and follows it.
- Test before drops or dye. A chemical splash is the exception: rinse first, then test.
- Recheck vision at every follow-up. A drop in acuity changes the plan.
Key feature 2 of 9
Serious or simple
Sort the red eye that threatens sight from the one that will settle on its own.
CFPC skill Clinical reasoningPhase History, physical, investigation, referral
On the exam
A 29-year-old with a red eye, pain in bright light and hazy vision. Expect a short menu (pick several from a list), then one best answer for where to send him.
Pick the findings that matter, then the next step.
Common mistakes
Calling it conjunctivitis and booking a routine visit. Pain in light with blurred vision needs an eye specialist urgently. Dilating his pupil before checking pupil and pressure is wrong too.
Approach
- Ask about pain, pain in bright light (photophobia), blurred vision, injury, contact lenses and past eye problems.
- Look at pupil size and shape, the cornea, and where the redness sits. Redness in a ring around the cornea points deeper than conjunctivitis.
- Stain the cornea with fluorescein, an orange dye. Look with a slit lamp, a lit microscope, when the story calls for it.
- Check the pressure when angle closure, a sudden rise in eye pressure, is possible. Don't dilate before you have checked the pupil and pressure.
- Angle closure brings severe pain, halos around lights, vomiting, a hazy cornea and a mid-sized pupil that reacts poorly.
- An older adult with new headache, jaw pain on chewing or sudden vision loss may have temporal arteritis. Treat it as an emergency.
- Unsure of the cause, or any red flag: refer urgently to an eye specialist.
| Cause | Clues | Today |
|---|---|---|
| Keratitis (infected or inflamed cornea) | Pain, light sensitivity, a white spot or stain on the cornea, contact lens wear | Urgent eye specialist |
| Acute angle-closure glaucoma | Severe pain, halos, vomiting, hazy cornea, poorly reacting pupil, high pressure | Emergency referral |
| Iritis (inflamed coloured part of the eye) | Aching, light sensitivity, small pupil, redness around the cornea | Urgent eye specialist |
| Penetrating injury | High-speed object, misshapen pupil, leaking fluid | Shield the eye, press on nothing, emergency referral |
Key feature 3 of 9
Metal in the eye
Suspect a fragment inside the eye from how the injury happened, and image when the story calls for it.
CFPC skill Clinical reasoningPhase Hypothesis generation, diagnosis
On the exam
A man felt something hit his eye while grinding metal without goggles. Expect a short menu (pick several from a list) of questions and next steps.
Pick the history that raises the risk.
Common mistakes
Calling it a surface speck because the eye looks quiet and he sees well. A tiny high-speed fragment can pass into the eye and leave little to see.
Approach
- Ask what the patient was doing: hammering metal on metal, grinding, drilling, or anything that throws fragments fast.
- Ask about eye protection. No goggles or safety glasses raises the risk.
- A small, fast fragment can enter with little pain and a quiet-looking eye. Trust the history over the look.
- Look for a tiny cut in the cornea or the white of the eye, a misshapen pupil, a hazy lens, or blood behind the cornea.
- With a high-risk story, arrange imaging and same-day eye specialist care, even if the exam looks normal.
- Suspect an open eye? Put on a hard shield, press on nothing, and refer as an emergency.
Key feature 4 of 9
Flip the lid
When something feels stuck in the eye, turn the lids out to find what hides beneath them.
CFPC skill Clinical reasoning, procedure skillsPhase Hypothesis generation, physical
On the exam
A woman felt grit blow into her eye on a windy day. Expect one best answer for the exam step that finds it.
Pick the exam step that finds it.
Common mistakes
Stopping at a clear-looking cornea and calling it a scratch. A speck under her upper lid scrapes the cornea with every blink.
Approach
- Ask the patient to look down. Turn the upper lid out over a cotton swab and look at its underside.
- Check the lower lid and the folds at the corners too.
- Stain with fluorescein. Fine up-and-down scratches on the cornea point to a speck under the upper lid.
- Sweep a loose speck away with a moist swab. Then recheck the stain and the vision.
- A rust ring, a speck in the centre of the cornea, or one that will not lift needs an eye specialist.
- No injury and nothing blew in? A lid search is not the priority. Look for the serious causes instead.
Key feature 5 of 9
Newborn eye infection
Tell a newborn's eye infection from a blocked tear duct, then treat the cause in the whole body.
CFPC skill Clinical reasoningPhase Hypothesis generation, treatmentSources Health Canada
On the exam
A 17-day-old with swollen lids and pus in both eyes. Expect a short menu (pick several from a list), then one best answer for treatment.
Pick the swabs, then the treatment.
Common mistakes
Calling it a blocked tear duct, or giving drops alone. Drops do not clear chlamydia from the rest of the body, and it can spread to the lungs.
Approach
- A blocked tear duct gives watering and crusting with a white, quiet eye. Swollen lids, red eyes and pus mean infection.
- Swab the eye for gonorrhea and chlamydia before you treat.
- Gonorrhea in a newborn's eye can damage the cornea fast. Treat it as an emergency with a pediatric team.
- Chlamydia in a newborn's eye needs an antibiotic by mouth, such as erythromycin. Drops alone are not enough.
- Chlamydia can also cause pneumonia in young infants. Ask about cough and fast breathing.
- The infection came from the birth canal. Test and treat the mother and her partners.
- A negative test early in pregnancy does not rule out infection at delivery.
Key feature 6 of 9
Which conjunctivitis
Tell allergic pink eye from infection, and a virus from bacteria, by the story and the exam.
CFPC skill Clinical reasoningPhase Diagnosis, historySources Health Canada
On the exam
A man with one gritty, watery eye, a tender node by the ear and a sick contact. Expect one best answer for management.
Pick the cause and the treatment.
Common mistakes
Antibiotic drops for his watery eye with a tender node. That is a virus, and drops will not shorten it. Calling it allergy is wrong too: allergy itches and affects both eyes.
Approach
- Itch is the clue to allergy. Both eyes, watery or stringy discharge, often with hay fever.
- Viral: one gritty, watery eye that often spreads to the other, a recent cold, and a tender node in front of the ear.
- Bacterial: thick yellow or green pus that glues the lids shut in the morning.
- Give antibiotic drops only when bacterial infection is proven or strongly suspected. Otherwise they are unlikely to help, and they risk breeding resistant germs.
- Viral pink eye spreads easily. Teach hand washing and not sharing towels.
- Any red flag moves the patient out of this box: pain in light, blurred vision, or contact lens wear.
| Type | Clues | Antibiotic drops? |
|---|---|---|
| Allergic | Itch, both eyes, watery or stringy discharge, hay fever | No |
| Viral | One gritty, watery eye first, recent cold, tender node by the ear | No |
| Bacterial | Thick pus, lids stuck shut in the morning | Yes, when bacterial infection is likely |
Key feature 7 of 9
Contact lens wearers
In a contact lens wearer with bacterial pink eye, pick drops that work against Pseudomonas.
CFPC skill Clinical reasoningPhase TreatmentSources Health Canada
On the exam
A young woman who sleeps in her contact lenses has a red, sticky eye. Expect one best answer for treatment.
Pick the drop, then the advice.
Common mistakes
A drop that misses Pseudomonas, a germ that can ulcerate her cornea. Missing a corneal ulcer under the redness is the bigger error.
Approach
- Contact lens wear raises the risk of Pseudomonas, a germ that can ulcerate the cornea quickly.
- Choose a drop that reaches Pseudomonas, such as ciprofloxacin. Its Canadian label lists Pseudomonas for corneal ulcers.
- Stain the cornea with fluorescein. A white spot, a stain, or pain in light means keratitis: urgent eye specialist.
- No contact lenses during treatment of an eye infection.
- Review soon. If the eye is not improving, refer.
Key feature 8 of 9
Steroid drops
Use steroid eye drops only where they help, like iritis, and keep them away from infection.
CFPC skill Clinical reasoningPhase TreatmentSources Health Canada
On the exam
A man with past iritis brings a leftover steroid bottle for a new gritty, watery eye. Expect one best answer.
Pick the safest management.
Common mistakes
Restarting his old steroid, or a steroid-antibiotic combination drop, for viral conjunctivitis. A steroid can prolong a viral infection and badly worsen herpes on the surface of the cornea.
Approach
- Steroid drops treat inflammation in the front of the eye, such as iritis.
- Never use them for herpes on the surface of the cornea (a branching ulcer), fungal infection, or most viral infections of the cornea and conjunctiva.
- An untreated, pus-filled eye infection is a reason not to use them. A steroid can hide it or make it worse.
- Stain with fluorescein first. A branching ulcer is herpes.
- Long use can raise eye pressure, damage the optic nerve and cause cataract.
- Beyond 10 days, use them only under an eye specialist, with pressure checks.
| Condition | Steroid drops? | Why |
|---|---|---|
| Iritis | Yes | Settles inflammation inside the eye |
| Viral conjunctivitis | No | Can prolong the infection |
| Herpes on the cornea's surface (branching ulcer) | No | Can make it much worse |
| Untreated bacterial infection | No | Can hide or worsen it |
| Fungal infection | No | Can worsen it |
Key feature 9 of 9
Look past the eye
In iritis, think of the body-wide diseases that can cause it, and ask about them.
CFPC skill Clinical reasoningPhase Hypothesis generationSources Choosing Wisely Canada
On the exam
A 29-year-old man with iritis settling on drops, and morning back stiffness that eases with movement. Expect a short menu (pick several from a list) of next steps.
Pick the work-up the history supports.
Common mistakes
A broad panel for lupus, sarcoidosis and more because a relative has lupus. Doing nothing is wrong too: his back stiffness makes the review of systems positive.
Approach
- Ask about each system: back stiffness, bowel symptoms, rashes or psoriasis, joint pain, mouth ulcers, cough, and sexual health.
- Back pain worse with rest, better with movement, with morning stiffness, points to ankylosing spondylitis.
- Other causes to ask about: Crohn's disease or ulcerative colitis, psoriasis, reactive arthritis and sarcoidosis.
- A first attack in one eye that is non-granulomatous (no large greasy spots on the back of the cornea), settles on treatment, and has a negative review needs no broad testing.
- That rule holds only when the review is negative. A positive answer earns tests aimed at it.
- Let the history and exam choose the tests. An untargeted panel costs more and finds no more.
Flashcards
Answer it first, then check.
KF 1A patient with a red eye left their glasses at home. How do you test acuity?
Through a pinhole, one eye at a time. It corrects most focusing error.
KF 2A red eye, pain in bright light and blurred vision. Is it pink eye?
No. Think of keratitis, iritis or angle closure. Refer urgently to an eye specialist.
KF 3Hammering metal on metal without goggles, and now a quiet eye. Safe to send home?
No. Suspect a fragment inside the eye. Arrange imaging and same-day eye specialist care.
KF 4Fluorescein shows fine up-and-down scratches on the cornea. Where is the culprit?
Under the upper lid. Turn the lid out and sweep the speck away.
KF 5A newborn has chlamydia in both eyes. Are antibiotic drops enough?
No. Give an antibiotic by mouth, such as erythromycin. Drops alone fail, and pneumonia can follow. Source: Health Canada
KF 7A contact lens wearer has bacterial conjunctivitis. Which drop do you choose?
One that reaches Pseudomonas, such as ciprofloxacin. No lenses until the infection is treated. Source: Health Canada
KF 8Fluorescein shows a branching ulcer. Can you start steroid drops?
No. That is herpes of the cornea, and a steroid can make it much worse. Source: Health Canada
KF 9First non-granulomatous iritis in one eye, settling on drops, negative review of systems. Order a panel?
No. Broad testing adds cost, not answers. Let the history and exam guide any tests. Source: Choosing Wisely Canada
FAQ
Which guideline does the exam follow for red eye?
The CFPC names none, and no Canadian guideline covers the red eye as a whole. The exam tests standard practice: check vision, spot the serious causes, and refer when unsure.
Do I need to use a slit lamp to answer these questions?
No. Know when it is needed and what it shows. Most marks go to the history, acuity, pupils, fluorescein staining, and knowing when to refer urgently.
Which red eyes need an eye specialist the same day?
Pain in bright light, blurred vision, severe pain, a white spot on the cornea, a misshapen pupil, a high-speed injury, or a painful eye in a contact lens wearer.
Is a sticky eye in a newborn always an infection?
No. A blocked tear duct gives watering and crusting with a white, quiet eye. Red eyes, swollen lids and pus mean infection, and need swabs and treatment.
Sources
Written from the CFPC Assessment Objectives and Canadian guidelines first. Checked by a Canadian family physician, MD, CCFP.
Last reviewed October 20, 2026For exam study. Not advice for a patient in front of you.
- Assessment Objectives for Certification in Family Medicine, 2nd editionCollege of Family Physicians of Canada · 2020
- Drug Product DatabaseHealth Canada
- Choosing Wisely recommendationsChoosing Wisely Canada