A few weeks ago I came across the following issue in one of our ergonomists’ reports. As it can definitely be a common issue with eyestrain, I thought I’d share it with everyone. I’ve taken most of the text directly from the report as written by our ergonomist, Kirsten Willms.

The client (we’ll call her Ms. Smith) was experiencing various types of discomfort while at her workstation, particularly eyestrain. The EWI ergonomist conducted an assessment and noted several changes that would help Ms. Smith work more comfortably. With regards to the eyestrain, one of the causes was the high light levels at her face when she faced the computer.

Ms. Smith’s desk was oriented so that she partially faced an uncovered window. Though the window was treated with an anti-reflection coating, the light levels at her desk were higher than the levels recommended by the CSA Office Ergonomics standard (CSA Z-412). The light hitting Ms. Smith’s desk was measured at 350 lux. However, the light at her face while facing her computer was 750 lux, much higher than the recommended 300-500 lux.  These high light levels were most likely contributing to her eyestrain symptoms.  Ms. Smith has had an extended monitor arm installed so that she can move her monitor more perpendicular to the window, however the layout of her desk (split surface corner unit) does not allow her to rotate her keyboard and mouse accordingly.  The following recommendations were recommended for their feasibility in order to reduce the amount of light reaching Ms. Smith’s face:

    1. The preferred solution is to install a mesh roller blind on the lower window adjacent to Ms. Smith’s desk.  This would allow some light to filter through while reducing the overall light levels.
    2. Consider an alternate screening device, such as the mesh “leaf” available at Ikea which could be placed in front of the window to filter light.
    3. Create a screen using plants on the window sill.
    4. Place a poster or bulletin board over the window.  This option however will completely block the light from the lower window.
    5. Alternatively, the location of Ms. Smith’s computer can be moved to her left side table.  This would involve the relocation of her CPU, bracket, storage panel, and storage pedestal, and preferably a user height-adjustable work surface should be installed.


While some people find there is not enough light, it is definitely possible to have too much! Check the lighting levels in your workplace so your staff can work more comfortably.