Employers with more than five staff members are required by law to undertake regular risk assessment for all employees who use display screen equipment for more than one hour at a time in their working day.
This means that your workers must be properly trained and regularly assessed. This information should be appropriately recorded on a formal DSE assessment document and in an up to date written risk assessment.
The form of the assessment needs to be appropriate to the nature of the tasks undertaken and the complexity of the workstation. For most office tasks the assessment can be a judgement based on responses to a pre-determined checklist.
Where particular risks are apparent, however, and for complex situations, for example where safety of others is a critical factor, a more detailed assessment may be appropriate. This could include a task analysis where particular job stresses had been identified, recording of posture, physical measurement of workstations, or quantitative surveys of lighting and glare.