Ophthalmic Instruments Viva: The Complete List With Uses and Traps

Start with the working end, not the eponym

An ophthalmic instruments viva is rarely testing whether you can recite a catalogue. The examiner wants to know whether you can look at an item, recognise what its tip and mechanism permit it to do, and speak safely about it. A name alone is incomplete. A list of three possible operations is worse: it sounds like guessing.

Use this answer every time:

“This is a [name]. I identify it by its [working-end/handle feature]. Its main role is to [broad task]. It differs from [confusion pair] because [one visible distinction].”

For example: “This is a Castroviejo needle holder. I identify it by the fine short jaws and spring handle with a lock. It holds a microsurgical needle during suturing. Unlike tissue forceps, it is designed to secure the needle rather than grasp tissue directly.” Then stop. Let the examiner choose the follow-up.

“Complete list” needs one caveat. Ophthalmic trays differ by procedure, service and manufacturer; retina, cornea, strabismus, oculoplastics and cataract sets contain many specialty variants. This is the core practical-exam list: instruments that repeatedly appear in general undergraduate/PG trays, together with the visual logic needed when the exact local eponym differs. It is exam education for doctors, not operative instruction.

The 30-second tray method

Before naming an item, sort it with seven visual questions. This prevents the common error of calling every fine instrument “forceps.”

1. Is there a blade, a jaw, a lumen, a measuring scale or a viewing element? This is the fastest functional split.
2. Does it have a hinge? A hinged instrument may be a scissor, clamp or needle holder. A spring-held instrument may be forceps or a speculum.
3. What is at the working end? Teeth hold; smooth jaws protect or manipulate; sharp opposed edges cut; an aperture/lumen delivers or removes fluid.
4. Is there a lock or ratchet? This suggests sustained holding or clamping. Do not equate a lock with a haemostat without checking the jaws.
5. Is the tip sharp, blunt, side-ported, curved or angled? State what you see. That is more defensible than guessing an eponym.
6. What scale is visible? Calipers measure. A scale is not itself a cutting or grasping clue.
7. What is the nearest look-alike? Give one contrast before the examiner asks it.

This is also how to answer an unfamiliar item. Say, “It appears to be a fine tissue-holding forceps because of the opposing toothed tips; I would confirm the exact pattern from the local set.” Do not invent a name. An honest morphology-based answer shows more clinical judgement than a confident false label.

Exposure and eyelid instruments

These are often the easiest marks because their design is conspicuous. The trap is assuming that every lid-opening instrument has the same name.

In a station, make the comparison explicit: a speculum holds lids apart without your hand; a Desmarres retractor requires you to hold it; a chalazion clamp fixes a portion of eyelid between plates. The examiner may then ask why the instrument is broad or smooth. The useful answer is mechanical, not patient-specific: broad smooth contact distributes contact over soft lid tissue; a fine sharp end is not appropriate for that task.

Forceps, holders and clamps: identify the contact surface

Most viva mistakes happen here. Residents see a small stainless-steel instrument and say “forceps.” First inspect what actually meets at the tip.

For a forceps follow-up, use this sequence: tip → teeth → task. “The 1 × 2 teeth allow tissue purchase, so this is a tissue-holding forceps.” For a needle holder, add jaw → lock → needle. Avoid saying that any forceps can replace a needle holder. In a practical exam, an examiner is testing recognition; in theatre, choice and handling are procedure- and supervisor-dependent.

Scissors and blades: say what cuts, then how the shape changes the task

All scissors have two blades, a pivot and opposed cutting edges. Their blade length, curve and sharpness are what turn a general answer into an ophthalmic one. Name the item if you know it; otherwise describe the configuration accurately.

One frequent examiner prompt is: “How will you distinguish Vannas from Westcott scissors?” A defensible answer is: “Both are fine ophthalmic scissors. Vannas has very small sharp blades for precise microsurgical cuts; Westcott scissors are generally more suited to delicate conjunctival/Tenon’s dissection. I would also state the straight or curved pattern in this tray.” That gives the contrast without pretending that every manufacturer’s design is identical.

Never demonstrate a cutting movement on a colleague, yourself or a patient in an exam station. Point to the cutting edges and describe their role. The broad literature on ophthalmic instrumentation itself reflects how specialised these designs are; a single eponym list cannot substitute for supervised local familiarisation (ophthalmic instrumentation review).

Measuring and marking instruments

Measuring instruments are high-yield because candidates often state a plausible number they have not actually read. In a station, read the scale first. If no unit is visible, say that you would check the engraved scale rather than guess.

The marking-versus-cutting distinction is worth rehearsing. A circular outline does not establish function. Ask: is the edge blunt for marking, or sharp for cutting? The answer carries more marks than merely recognising a circle.

Cannulae, irrigation–aspiration and manipulation tools

A cannula has a lumen. Find its port before you answer. A sharp needle, a blunt cannula, a side-port aspiration cannula and a powered handpiece should never be treated as interchangeable.

The safest cataract-tray viva answer separates energy, fluidics and manipulation. A phaco handpiece belongs to the energy category; a Simcoe device to manual irrigation–aspiration; a cannula to delivery; a Sinskey hook or dialer to manipulation. Do not convert this classification into a stepwise surgical recipe. The practical station asks you to identify the device, not perform the procedure.

Examination items that commonly join an instrument tray

Not every station is an operating tray. Some mix examination equipment with surgical instruments. Give the same four-part answer, then add the optical or measurement principle only when asked.

If you need to repair terminology while revising a mixed station, use the verified ophthalmology glossary. For the optical distinctions, revise the principle rather than trusting a photograph alone; angle and fundus lenses can look deceptively similar at speed.

Ten classic confusion pairs

Memorise comparisons, not alphabetical lists.

1. Speculum vs retractor: self-retaining lid separation versus hand-held lid retraction.
2. Chalazion clamp vs forceps: ring-and-plate compression of a lid segment versus direct grasping jaws.
3. Toothed tissue forceps vs tying forceps: teeth for tissue purchase versus smooth tips for suture handling.
4. Forceps vs needle holder: direct grasping versus locking jaws designed to secure a needle.
5. Vannas vs Westcott: very fine microsurgical blades versus delicate conjunctival/Tenon’s scissors.
6. Keratome vs MVR blade: each is sharp, but profile and set context differ; name the blade shape you see.
7. Marker vs trephine: leaves a reference mark versus circular cutting edge.
8. Rycroft/viscoelastic cannula vs sharp needle: blunt lumen-bearing delivery instrument versus sharp needle.
9. Simcoe vs phaco handpiece: manual irrigation–aspiration versus ultrasound-enabled phaco device.
10. Sinskey hook/dialer vs IOL forceps: manipulation tool versus grasping jaws.

When an examiner changes the brand or pattern, this comparison-first method survives. It also stops a risky habit: treating eponyms as if they determine a single procedure or action.

A five-minute revision drill for a tray station

Build a card for each item with only four fields: a sketch/photo, the working-end clue, one primary role and one confusion pair. Then run this drill with a covered tray or image set:

1. Recognition, 10 seconds: uncover one instrument. Classify it as exposure, grasping, holding, cutting, measuring, cannula/manipulation or examination.
2. Answer, 20 seconds: give the four-part spoken answer. Do not add a procedure unless asked.
3. Contrast, 10 seconds: name the nearest look-alike and one difference.
4. Reset, 10 seconds: put it into the correct functional group and move on.

After ten instruments, repeat only the misses. Photograph labels from your own department’s teaching tray only where permitted, because local eponyms and patterns vary. For operating-room use, instrument choice, assembly, sterile processing and handling must follow local policy, manufacturer instructions and direct supervision. Reprocessing is not a minor detail in intraocular surgery; the literature on toxic anterior segment syndrome includes instrument-cleaning factors, which is why this article deliberately does not offer a homemade cleaning protocol (peer-reviewed review).

For a structured image-and-list revision route, see Instruments in Ophthalmology notes. If your practical station combines devices with drugs, Instruments & Drugs for Practical Exams/Viva is the adjacent topic route. Rehearse the spoken station format through the OSCE, Practical & Viva Voce Ready bundle. These are revision resources, not a replacement for supervised local instrument training.

For broader formal learning indexes, the American Academy of Ophthalmology education catalogue is a verified professional-college gateway. It does not define the contents of your department’s instrument tray; revise that local set separately.

Sources

• Ophthalmic instrumentation — PubMed-indexed review (accessed 18 August 2026).
• Toxic anterior segment syndrome: role of enzymatic detergents used in cleaning intraocular surgical instruments — peer-reviewed article (accessed 18 August 2026).
• American Academy of Ophthalmology education catalogue (accessed 18 August 2026).