Indirect glare is a type of visual discomfort caused by light reflecting off surfaces instead of coming directly from a light source.
Specifically, indirect glare is caused by reflection and back radiation from reflective and shiny surfaces. This occurs when light from a window, lamp, or other source bounces off surfaces like walls, desks, computer screens, or floors into your eyes.
Understanding Indirect Glare
Unlike direct glare, which comes straight from a bright source (like staring at the sun or an unshielded light bulb), indirect glare is all about bounced light. Think about sunlight reflecting off a white wall or light from an overhead fixture bouncing off a glossy table into your eyes.
Sources of indirect glare can include:
- Shiny desk surfaces
- Glossy walls or paint
- Reflective floors
- Glass surfaces (windows, framed pictures)
- Polished furniture
- The computer screen itself (reflecting surroundings)
Why Indirect Glare is Problematic
Indirect glare can be quite strenuous for the eyes. As noted in the reference, such indirect glare is particularly strenuous at a computer workstation, because the eye tries to “switch off” the reflection and absorb the monitor content.
When your eyes encounter a reflection while trying to focus on something else, like text on a screen, it creates visual competition. Your eyes have difficulty distinguishing between the intended target and the distracting glare, leading to:
- Eye strain
- Fatigue
- Headaches
- Reduced concentration and productivity
This constant effort to 'switch off' the reflection adds to the workload of your eyes, making it hard to focus and potentially causing discomfort over time.
Reducing Indirect Glare
Fortunately, indirect glare can often be minimized with simple adjustments. Here are a few strategies:
- Modify Surfaces: Use matte finishes on desks, walls, and floors instead of glossy ones.
- Reposition Light Sources: Move lamps or adjust window blinds/curtains so light doesn't directly hit reflective surfaces within your line of sight.
- Adjust Workstation Layout: Position your desk so your computer screen is perpendicular to windows, avoiding direct light or reflections on the screen.
- Use Anti-Glare Filters: Apply a matte filter to your computer monitor or glasses.
- Optimize Room Lighting: Ensure ambient lighting is balanced and doesn't create harsh reflections. Avoid positioning task lighting where it can reflect strongly off your work surface.
By understanding the causes and impacts of indirect glare, you can take steps to create a more comfortable and visually ergonomic environment, especially in areas like computer workstations where focus and visual clarity are critical.
