Date/time
Thursday 29th October 2026. Chaired by Helena Lee (University of Southampton). Vice-chair: Rebecca McLean (University of Leicester).
Meeting recording
Attendees
Larry Abel, Amanda Douglass, Matt J Dunn,Herbert Jaegle, Helena Lee, Rebecca J. McLean,Rasha S. Moustafa, Fiona Bríd Mulvey,Jay Self, Andreas Sprenger.
Apologies received from: Frank A. Proudlock, Herman Talsma, and Gemma Arblaster
Notes
1. Previous minutes and purpose of meeting
The minutes of the previous meeting were reviewed with no objections raised. Helena Lee reminded the group that members had been asked to propose wording for the first recommendation concerning fixation/viewing distance; these submissions had subsequently been collated by Helena Lee and Rebecca J. McLean.
The principal aim of this meeting was therefore to reach consensus on this first element of the fixation guidance before moving on to subsequent recommendations. Because iterative polling was required, Rebecca J. McLean led the presentation while Helena Lee administered the polls.
2. Overall structure of the viewing-distance recommendation
The group considered four broad approaches:
- one fixed default viewing distance;
- more than one routine condition, such as near and distance;
- a permissible numerical range or defined bands; or
- no mandatory numerical distance, with testing determined by the clinical objective.
Initial polling did not produce the required consensus. Discussion highlighted a tension between maintaining comparability between centres and producing guidance sufficiently pragmatic and flexible for routine clinical use and non-expert users. Fiona Bríd Mulvey favoured fixed, defined distances over an unrestricted numerical range because this would improve comparability. Larry Abel emphasised the value of much closer testing where convergence effects need to be assessed.
The group increasingly converged on a model consisting of one default initial distance with additional predefined distances used when clinically indicated, rather than requiring multiple distances in every patient. The chat discussions supported this approach, including wording around three fixed distances and testing alternatives according to clinical indication.
Decision
Use one standard default initial testing distance, with defined optional near and beyond-near distances where clinically indicated. The optional distances will not be mandatory for every fixation assessment.
3. Default initial testing distance: 70 cm
The group considered 60 cm and 70 cm as potential standard distances. Following polling and discussion, consensus was reached on 70 cm as the initial mandatory/default testing distance.
The intention is for 70 cm to provide a reproducible starting point for fixation screening without implying that every clinically relevant assessment must be undertaken at that distance. The wording should therefore make clear that additional testing is undertaken if clinically indicated rather than making multiple conditions obligatory.
Decision
70 cm will be the default initial viewing distance for the fixation-screening recommendation.
4. Optional near and beyond-near distances
The group discussed whether additional predefined distances were necessary to identify abnormalities that might not be evident at 70 cm.
Larry Abel described the use of very-near testing at approximately 15 cm when assessing convergence-related changes, particularly where infantile nystagmus is suspected. Fiona Bríd Mulvey highlighted other situations in which abnormalities may become apparent only at near fixation. These examples persuaded members who had initially favoured a single-distance screening test of the value of having additional predefined options.
The meeting subsequently considered the actual distances. The discussion and chat converged on:
- 70 cm: default initial distance
- 40 cm: optional near condition
- 15 cm: optional beyond-near/very-near condition
Helena Lee asked whether members were content with 40 cm and 15 cm as the two optional conditions and recorded that the group had reached agreement.
Decision
The fixation guidance will therefore be developed around:
70 cm default + 40 cm near option + 15 cm beyond-near option, with the latter two undertaken when clinically indicated rather than routinely in every participant.
5. Eye-tracker configuration and equipment constraints
A substantial discussion considered whether fixed viewing distances are practical across different eye-tracking systems.
Rebecca J. McLean raised manufacturer-specific operating-distance requirements. Andreas Sprenger distinguished the camera-to-eye distance, which relates to eye-tracker recording, from the eye-to-display/fixation distance, which is the relevant parameter for the fixation recommendation. Many systems permit these to be adjusted independently, although the group noted that this is not possible with every configuration.
Members therefore considered it important that the guideline should not unnecessarily exclude equipment because of hardware configuration. At the same time, using defined viewing distances was considered valuable for clinical and research comparability, provided deviations can be reported.
Agreed approach
The guideline wording should:
- clearly distinguish fixation/display distance from camera-to-eye operating distance;
- recognise equipment where these distances cannot readily be separated;
- specify the preferred standard distances where the equipment permits them; and
- ensure that departures from the recommended distances can be explicitly documented.
A footnote or explanatory qualification was proposed for systems where camera and display positioning cannot be independently adjusted.
6. Reporting of viewing distance
The group highlighted the importance of knowing and reporting the actual viewing distance used. Fiona Bríd Mulvey noted that viewing distance is not consistently reported, while Jay Self emphasised the practical principle of measuring and recording the distance even where a standard distance cannot be achieved.
This provides a balance between standardisation and accessibility: the preferred distances improve cross-centre comparability, while a justified deviation does not necessarily prevent the remainder of the protocol being followed.
7. Low vision and adaptations
Rasha S. Moustafa raised concern that a fixed 70 cm requirement might disadvantage people with low vision, particularly children and people with nystagmus, and stressed that the guidance must avoid an unsuitable standard setup being interpreted as a failed assessment.
Matt J Dunn noted that stimulus visibility should be defined in terms of visual angle, allowing stimulus size to be adjusted for viewing distance. Fiona Bríd Mulvey suggested considering established approaches from low-vision/perimetry guidance rather than developing visual-angle recommendations without reference to existing practice.
Outcome
No final recommendation on adaptations was made. Low-vision adaptations and target visual angle remain items for subsequent discussion.
8. Items deferred to the next stage
Having agreed the basic viewing-distance framework, the following remained outstanding:
- the final wording of the viewing-distance recommendation;
- requirements for head-mounted systems and whether separate sub-recommendations are required;
- minimum mandatory reporting fields;
- how deviations/adaptations should be handled;
- target size and visual-angle guidance, including low-vision considerations.
The group agreed to complete the viewing-distance section before progressing to the visual-angle question.
9. Meeting process and future scheduling
Running the presentation, changing polls and monitoring discussion simultaneously proved difficult. Helena Lee proposed having a third person monitor the Teams chat and raised hands at future polling meetings. Matt J Dunn volunteered to assist with this.
The group also discussed the burden created by meeting times across international time zones, particularly for Australian participants. Helena Lee indicated that further meeting dates would be considered, with time-zone balance taken into account.
Actions
| Action | Responsibility |
| Collate the agreed viewing-distance decisions and incorporate them into the first guideline recommendation: 70 cm default; 40 cm near; 15 cm beyond-near, with the latter two optional according to clinical indication. | Helena Lee / Rebecca J. McLean |
| Add wording/footnote addressing separation of fixation/display distance from camera-to-eye distance and equipment that cannot accommodate the preferred configurations. | Helena Lee / Rebecca J. McLean |
| Develop the approach to low-vision adaptations and subsequently address visual-angle recommendations, with consideration of existing low-vision/perimetry guidance. | Subcommittee |
| Continue the outstanding viewing-distance issues, including head-mounted systems, adaptations and minimum reporting fields, at a subsequent meeting. | Subcommittee |
| Arrange additional meeting dates with greater consideration of international time zones. | Helena Lee |
| Introduce a third facilitator to monitor chat and raised hands during future polling sessions. | Helena Lee / Matt J Dunn |
Key consensus from the meeting
Fixation/viewing distance
For initial assessment of fixation, a viewing distance of 70 cm should be used as the default testing condition. Where additional assessment is clinically indicated, near fixation should be assessed at 40 cm and beyond-near fixation at 15 cm. Near and beyond-near testing are optional extensions and are not required as part of every assessment. The actual viewing distance(s) used should always be recorded and reported.
Where patient requirements or equipment configuration prevent testing at a recommended distance, an appropriate alternative distance may be used, and the deviation should be documented.
Note: Viewing distance refers to the eye-to-fixation target/display distance, rather than the camera-to-eye operating distance of the eye-tracking system.