1. Need a quick refresher?
Check out our mini YouTube course and glossary on visual perceptual conditions.
Training
Training
Ways to get up to speed with the Oxford Visual Perception Screen:
1. What are visual perception difficulties?
Or find a definition of each of the difficulties that OxVPS screens for in the table below.
| Simultanagnosia | inability to perceive more than one object at a time. |
| Apperceptive agnosia | inability to combine different features of an image (colour, shape, texture) into a coherent whole that is an object. While knowledge of the object is intact, people are unable to perceive the correct form of the object, and therefore find it difficult to recognize, draw, or copy an object based on visual information alone. |
| Associative agnosia | difficulty with understanding the meaning of what is seen. Although patients perceive an object’s features like size, shape, or colour correctly and can describe it, they cannot link it to visual representations of objects in their memory. Patients can draw or copy but do not recognise what they have drawn. |
| Optic aphasia | inability to name visually presented objects without difficulties in naming those objects on tactile or auditory presentation. |
| Cortical blindness | total or partial loss of conscious functional vision caused by damage to the brain’s occipital cortex. |
| Akinetopsia | “motion blindness”, difficulties with perceiving object in motion, severity might vary. |
| Achromatopsia | “colour blindness”, distorted colour perception. Patients can see everything in grayscale or might have difficulties telling similar colours apart. |
| Neglect dyslexia | consistent letter omission, addition, and substitution errors on either the left or right side of a word when reading individual words. |
| Alexia | “word blindness”, inability to comprehend written material. The patient’s ability to write and spell can be intact, but they are unable to spontaneously read. |
| Global attention deficit | inability to attend to global shape of an image and instead focusing on small details in the image which can hinder recognition of objects. |
| Visuo-constructive deficit | difficulty in construction tasks relying on visual information, such as drawing or assembling the various parts of an object into a complete structure. |
| Space-based neglect | visual inattention to either the left or right side of space. |
| Object-based neglect | visual inattention to either the left or right side of an object regardless of where the object is in space. |
| Prosopagnosia | also called face blindness, is a cognitive disorder of face perception in which there is an inability to recognize familiar faces, including one’s own. |
| Anton-Babinsky syndrome | total loss of vision, although patient is convinced their vision is normal. |
| Blindsight | the total or partial loss of conscious functional vision caused by damage to the brain’s occipital cortex but preserved unconscious vision. Patients can use their unconscious vision in automated behaviours like avoiding obstacles. They will deny any functional vision, but answer correctly more often than expected when forced to guess. |
2. Training Videos
The figure copy task and reading task are a bit more challenging to score, but we have a series of example videos with a few tricky cases to help you understand the scoring.
3. Manual
4. FAQs
What do you mean by visual perception?
Visual perception refers to how the brain interprets what the eyes are seeing. You can find information about visual perception conditions in our glossary.
How do I get started with OxVPS?
Register to use it, download the tools, and watch the training videos. It is free for professionals working in research or publicly funded healthcare.
How do I present the stimulus to patients?
We recommend printing the stimulus book out and laminating the pages with mat lamination paper to reduce glare. There are also online printing companies which can print and bind the book if you prefer. We advise the bind the pages at the top, along the short side.
How do I learn how to administer OxVPS?
Watch the videos about administration and scoring. Administer it to a colleague. Practice makes perfect! The more you use OxVPS the easier administration will be. We suggest administering it with every patient to enhance your use but also to screen your patient for visual perception difficulties.
Has OxVPS been validated?
Yes, it has been validated in stroke patients. We conducted a diagnostic accuracy study with over 200 stroke survivors. Read about the results on our research pages. It has not yet been validated in other populations. Please drop us an email if you are interested in taking such a research project on, we are keen to support you.
What is the reliability of OxVPS?
We evaluated inter-rater reliability of OxVPS: one person administered OxVPS with a patient and scored all tasks on the spot or shortly after administration, a second person scored all task from a video recording of the administration. We did this for over 100 stroke survivors and found good agreement between both people scoring OxVPS. Check out our research for more details.
What was the development process of OxVPS?
For the development of OxVPS, we started from what health professionals told us was challenging in current practice. We held a focus group, interviews, and a national survey in the UK. The conclusions from that research were that there is insufficient training on the topic and existing standardised assessments are too time consuming. We then developed a prototype and gathered feedback from stroke survivors and older volunteers. We got over 500 comments and went through 30 different prototypes before we realised OxVPS 1.0. We then collected normative data from 80 healthy volunteers and validated OxVPS 1.0 with 24 stroke survivors. Some tasks still required some adaptation because they were too difficult or not suitable for patients with low visual acuity. We then made OxVPS 2.0. Again, we went out in the community and collected normative data from over 100 healthy older volunteers to determine cut-off scores for normal performance on each task of OxVPS. A large-scale study on reliability and validity with 200 patients has also be completed and initial findings were presented at conferences in 2023-2024. You can find all the information about developing OxVPS 2.0 on our research pages.
How strict should I be when scoring the reading task?
We don’t want the scoring of OxVPS to become a burden. The tool is for information gathering. We understand that some patients may have not read out loud for years, or they may feel rushed because they feel they are being ‘tested’ or perhaps they do not pronounce the possessives/plurals of some words. For some patients English might not be their first language or their pronunciation is influenced by a local accent. We do not penalise patients for such mistakes. Patients with aphasia, with low literacy levels, or with very low visual acuity might not be able to read the paragraph. As with all tasks of OxVPS, using your judgement as a clinician for the scoring is essential. All errors, observations, and scores should be interpreted holistically and with a patient’s other abilities in mind. If the patient misses all the bold words, or perhaps only reads from the middle to the right, or even left to middle this is providing you with valuable information about how the patients is perceiving the words. If you are unsure, you can watch a few examples of scoring the reading task.
How strict do I need to be when scoring the figure copy?
Scoring the figure copy is subjective. We don’t want the scoring of OxVPS to become a time consuming task. If some lines are a little wobbly, or don’t meet up perfectly you don’t have to deduct points. The tool is for information gathering. Think about what information you have gained from the figure copy, rather than if the scoring is perfect. For example, if your patient only draws half the figure, or misses out the border or inside components then you know they are seeing the world in a very different way. If you are unsure, you can watch a few examples of scoring the figure copy task.
I’m concerned that I might be over diagnosing patients, what do you recommend?
OxVPS is a screening tool. It is designed to provide you with a way of gathering information about your patients. This means it not a diagnostic tool, but rather provides a way for health care professionals to gain more insight into a patients which may require further investigation and or referral to specialist services, for example an orthoptic or neuropsychological assessment.