The OSCES, Selective Attention and the Invisible Gorilla

First Published in Optometry Today, May 2011

History: why did the College implement the move?

The College introduced the OSCE’s, or Objective Structured Clinical Examinations a few years back as a forward move to a system of pre-registration examinations that were seen to be less biased, impartial and non-discriminatory.

Like many significant changes in any organisation, these changes were met with some degree of resistance. However, the College recruited a large team of experienced examiners who were set the task of creating the content of each station, and were therefore heavily involved in the development of the new exam system. The knowledge and experience gained from years of cumulative examiner experience ensured that the outcome of each station had a single purpose: to ensure that the trainee would be ‘safe to practise.’ So these exams are less of the radical change than was originally expected and are rather an onward development of the old system. In summary: similar content, different method, fairer system.

Love them or hate them, and we all have our opinions, they are here to stay. But the OSCE’s are not a new concept by any means and neither have the College reinvented the wheel when redesigning them. OSCEs have been around for some time and what the College has done is to closely look and study OSCE’s already in place with allied health professions such as medicine, and have adapted them for optometry.

The term objective in this setting means that the exams are designed to move away from subjective vivas. There is almost no examiner interaction and each examiner is there to ensure that you complete the test in a safe and orderly manner before marking the station when you exit. Therefore there is no need to work on your interaction with the examiner or worry what they are going to ask you. However, what this does mean is that you must focus on your interaction with the patient instead.


Trainees may take confidence in the fact that they have already come so far in their training year. In achieving the Stage 2 pass, trainees have been assessed in all core competencies by experienced assessors. So the OSCEs are, if you like, a check test to validate those results.

The most commonly asked question trainees ask is ‘where do I start?’ Whilst almost anything may be examined in the OSCE’s, there is no point going back to the beginning. You can’t possibly cover it all. And neither should you need to.

First of all, these exams are clinical based, it says so in the title. So if you have to have a focus at all, be it on the practical. There are four key areas of focus that I would recommend you cover, all of which contain significant pass/fail criteria:

1. Investigation

2. Interpretation

3. Management

4. Communication


This is where you may be asked to demonstrate a technique. Here the examiner will mark you on how well you use the equipment, how you communicate with the patient, and how you explain the test.

Example – use of an Amsler Chart

You may be asked to use this technique on a patient. But before you pick up the chart take a step back and think. What should you do first?

  • Check if the patient requires a near correction.
    • Ask them to wear it.
  • What working distance should you hold the chart?
    • Is there a tape measure?
    • If so, use it.
  • Which chart is the most appropriate to use for the presenting complaint (there are several)
    • Select the correct one.
  • What lighting should you use?
    • Is there a lamp on the table?
    • If so, use it.
  • How do you explain the test to the patient?

The way you set up and perform a test will give the examiner a great deal of information on whether or not you understand the purpose of that test. So look at all of the equipment that is there.

Selective Attention and the Invisible Gorilla

Candidates who are so focused on one thing may miss the obvious. This is called selective attention. A well known experiment, available to watch on You Tube illustrates this beautifully (simply Google: ‘selective attention test’). You are asked to watch a short film of two teams of three basketball players. One team are wearing white and the other team are wearing black. Each team has a ball and are throwing it to each other whilst they all intermingle. You are asked to count how many passes the white team make to each other. The viewer will focus so closely on the white team that nine times out of ten, they will not see the man in a gorilla suit walking into the room, waving and then walking out again. Highly amusing a worth a look. But then transpose this to the OSCE cubicle.

Myself and a colleague set up a cubicle to ‘test’ this theory. Students were asked to select the most appropriate Amsler chart for the presenting condition and perform the technique accurately. Everything they needed was on the table, including a tape measure, which is critical to set the correct working distance of the test plates. However, not one person used the tape measure. And yet the test requires that a working distances accurately measured and each student had been taught this. Each student was so focused on choosing the correct Amsler plate that they failed to actually see the tape measure. Even when the tape measure was placed on top of the book of Amsler plates, they simply moved it out of the way. So, take a look at everything in the room. Try to see the whole picture. Whilst we can try to design stations without an invisible gorilla, there are some that we cannot avoid.

Interpretation: methodical and logical

Some stations may ask you to look at the data presented, and perhaps make a judgement call. For example, you may be asked to interpret a prescription, make an order or communicate the data to a patient. When you are presented with a page of information work through it logically, there may be red herrings, additional information that may not be relevant. But that is the same for most patients sitting in your consulting room chair. For example if you are given a fundus photograph don’t go straight for the obvious lesion in the centre, do what you would normally do when performing fundoscopy. Start at the disc, work your way our along the vessels etc. Did you see the melanoma in the far periphery? Another invisible gorilla just waiting to be overlooked.


Here you may be asked to communicate the management of the presenting condition to a patient. For example, you are asked to interpret the data given and manage the patient accordingly, by communicating this information to the patient and successfully addressing their fears or anxieties. Of course it does mean that you must make the correct judgement call on your referral. Consider the following when you are making a referral: Who? When? Why? Where? How? Wherever possible put a specific time to your referral. ‘Soon’ is too vague. The examiner wants to hear you give the patient a more specific timeframe, such as ‘same day.’ When I tell my children they are going to the swimming pool ‘soon,’ this could be in twenty minutes time, or it could be some time next week. Everyone’s interpretation of ‘soon’ is quite different. That said, we rarely get to the pool in time.


Your techniques, your methods and how you present yourself when talking to patients is critical. It says a lot about you and your understanding of their condition, and your abilities. Not surprisingly then Communication has a significant weighting in these exams. However, if you ultimately miss a diagnosis, no matter how ‘communicative’ you are (and some of you are very effective) you will fail the station. After all, if you inappropriately refer, you are not ‘safe’ to practise. So work consistently on the patient journey and their experience. You need to be able to communicate effectively, appropriately and accurately. Focus on how you ask questions, how you develop your questions in line with the patient’s responses and ensure that you are able to extract every last relevant detail from the patient.

Who are the patients?

In the past the College used real patients for the exams. For example there was always a diabetic fundus, someone with a longstanding palsy and someone with cupped discs. But to ensure a fair an equal system then all trainees should have seen the same patient at each exam centre and clearly this is not feasible. Furthermore, these patients were notoriously hard to come by. So such days are also gone. And I must say I am glad too. In the past I have spent hours on end trying to secure appropriate patients for exams and courses with minimal success. So what we do now is to have trained actors. It may sound an unrealistic concept but for the purpose of these exams it works well, and is extremely effective. It is not who you see here but it is the scenario that the actor is given to act out that is important and this adds to the consistency of these exams. So if you think your spied your motility patient in the last episode of Dr Who, the chances are you are probably correct. Where an actor is used you can rest assured that they have been given enough detail to be able to act out their role. The actor will then respond to you in the manner that they have been asked. For example, they may have been asked to play a patient that is nervous about going to hospital. So don’t treat this like an artificial situation that it probably is. Just talk to them in the same manner you would if they had visited your own practice.

The killer station: is there or isn’t there?

Well, if the exams are to remain objective then no, there is not. There is no one single station that you must pass, or all is lost. However, in each station there will be similar pass/fail criteria year on year. Are you safe to practise? This has, and always will be the ‘killer’ for want of a better word, because if you are not safe then you cannot be allowed to practise. And I think that we can all agree with that one. Referral criteria is not something you can find in a book, and comes primarily from your experience in practice, so in conclusion whilst preparing for these exams:

1. Focus on continuing to consolidate your practical skills

2. Focus upon your ability to interpret data in a quick and methodical fashion

3. Focus on your referral criteria and the patient journey

4. Focus upon your communication skills

And don’t forget to look for the man in the Gorilla suit. There is one at every exam centre, just asking to be overlooked. Good luck!

Jane Macnaughton MCOptom

Booking Now: A Trip to the OSCE’s: CLEARVIEW Training’s Mock Exam Course for OSCE Preparation.


  1. I first saw this article in OT and gave it to my Prereg. Very informative. Thank you. Good luck with your exams everyone.

  2. Just took my exams this week. Didn’t see this article in time but it makes a lot of sense now. Mood luck everyone with the result!

Leave a Reply to Prak Cancel reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s