Using a Computer Monitor or TV as an EMDR Light Bar

A traditional EMDR light bar is a horizontal strip of lights that moves a point of light left and right for the client to follow. Any screen that can display a smoothly moving stimulus across its width can serve the same purpose: a laptop, an external monitor or a TV connected to a computer. This article explains how to set that up and where the approach has limits.

What is established: eye movements are the original and most-studied form of bilateral stimulation in EMDR (Shapiro, 2018).

What the literature does not establish: there is no universally agreed clinical standard for screen distance, visual angle, eye-movement amplitude or optimal screen size. Experimental studies have used a variety of set-ups, and protocol texts describe adjusting stimulation to the individual client. Any specific distance or size presented as "the correct one" should be treated with caution.

What is uncertain: whether a screen-based stimulus and a dedicated light bar produce different clinical outcomes has not, to our knowledge, been compared directly in published trials.

In practice the goal is simple: the client should be able to follow the stimulus comfortably from one side to the other with their eyes, without moving their head much and without strain. Everything below serves that goal.

1. Connect the screen to the computer that runs the BLS tool (or, for online sessions, the client uses their own screen).
2. Open the visual stimulation and switch to fullscreen so browser bars and notifications do not distract.
3. Choose a stimulus with good contrast against the background.
4. Run a short test and ask the client whether they can follow it from edge to edge.

Place the screen roughly at eye level and centred on the client. The client should be able to see both edges while looking straight ahead. If they must turn their head to follow the stimulus, the screen is too close or too wide for them; if the movement feels tiny, it is too far. Because no universal distance has been established, adjust with the client rather than measuring to a fixed number.

Fullscreen removes visual clutter. Lower the screen brightness in a dim room so the display does not dazzle, and avoid very bright, high-contrast flashes. Ask about discomfort; clients with light sensitivity, migraine or a history of photosensitive seizures need particular care, and some may be better suited to auditory or tactile BLS.

Horizontal left–right movement is the classic pattern (see horizontal eye movements). Diagonal, infinity or pendulum patterns are variations offered by many tools; there is no strong evidence that one pattern is superior. Speed is discussed in BLS speed and set length.

A wider screen gives a wider movement, but a laptop held at a sensible distance can still provide a full side-to-side sweep. More on the trade-offs in EMDR light bar.

Low-powered devices or many open browser tabs can make movement stutter. Screen refresh rates vary. Power-saving modes may dim or lock the screen during a set. Close other applications, keep the device on mains power and test before reprocessing. Background on visual stimulation is in visual bilateral stimulation; research context is in the research library.