Many modern cars use high brightness LEDs for their rear lights. They tend to be rapidly switched on and off for 'normal intensity' and fully on for 'high intensity' when the brakes are also applied. When driving behind these cars I find the LED lights very distracting - whenever I move my eyes from one spot to another the lights appear to leave a trail of very bright dots caused by their rapid switching. Normal incandescent bulbs do not look like this, nor do the LED car lights when they at full intensity. Domestic items with LED displays also tend to do the same thing (I noticed it on a washing machine today). I also see it to a lesser extent with fluorescent lights.

My daughter also sees the flickering car lights when moving her eyes, but my son does not, and neither do other people I've asked. I understand why LEDs are rapidly switched in this way, and why they appear as a string of dots when I move my eyes - my question is why do some people apparently not see the effect? Is our perception somehow different? I have read reports that the brain 'switches off' visual processing when the eyes are flicked from one point to another - could this 'switching off' vary from one person to another?