It is the time of year when decorations appear everywhere and everyone has a preferred style, from bright flashing lights to something more understated. Christmas decorations are meant to be cheerful, yet for some people, certain types of visual input can be surprisingly difficult to tolerate.

No one wants to dampen the festive mood, but it is worth knowing that decorations can cause discomfort in ways that are easy to overlook.

Flashing lights are a familiar Christmas choice, probably because they grab attention. We have known for a long time that flashing lights can trigger seizures in people with epilepsy because rapid flashes can synchronise activity in parts of the brain that are already more susceptible to overstimulation.

Autistic people can also be sensitive to flashing lights because many autistic people have heightened sensory responsiveness. People with migraines may be affected because bright, flickering contrast can stimulate the visual cortex and lead to headaches.

Even without these conditions,

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