When driving a car or riding a bike, you should also think about other road users aside from yourself. Even though flashing lights can sometimes be beneficial to you as a biker, you have to consider that it can trigger various reactions from other people.

One of the most talked-about issues regarding flashing bike lights is its tendency to trigger seizures, especially photosensitive epilepsy. But can flashing bike lights really cause seizures? If yes, what are the alternatives to flashing bike lights which we can use instead?

This blog will try to answer these questions and understand the relationship between flashing lights and seizures.

What is photosensitive epilepsy?

Photosensitive epilepsy is a seizure triggered by bright flashing lights or patterns. This is diagnosed through an electroencephalogram or EEG, in which a person is made to look at flashing lights with different speeds or patterns.

These flashing patterns bring erratic changes to the brain activity of the affected person. It can be triggered by various lightings such as television broadcasts, screen monitors, video game graphics, and even the erratic changes of natural outdoor lighting coming from the sun.

The level of a person's photosensitivity is based on the frequency of the light changes, the brightness, and the distance from the light source. In most cases, low-output light may not cause distress among affected people, even with flashing patterns. 

However, a low-output light placed against a dark background creating a high contrast can be a great trigger of seizure.

This is why most clinical and medical research concludes that the brightness level, frequency pattern, and other factors causing photosensitive epilepsy still vary from person to person. 

Can flashing bike lights cause seizures?

The answer to this question is yes. Flashing bike lights can cause seizures—alongside pretty much all kinds of flashing vehicle lights.

However, this doesn't really mean that bike lights are totally dangerous. 

First off, what you should know is that not everyone diagnosed with epilepsy has photosensitive epilepsy. Based on clinical research, only 3 out of 10 people diagnosed with epilepsy have photosensitive epilepsy.

Furthermore, some researchers concluded that only 1 out of 4000 people might be sensitive to bike lights. These statistics remarkably prove that your flashing bike lights are generally safe for road use.

But then again, even the slightest chance of affecting other road users can be dangerous. This is why it's essential to always keep your bike lights within the suggested brightness and luminosity to avoid seizures and even headache triggers, among other people.

How to avoid triggering seizures with your flashing bike lights?

The best way to avoid triggering seizures is to skip on continuously flashing bike lights.

Continuous flashing taillights aren't really that beneficial. Most of the time, they just confuse and disorient other road users. There are already numerous smart bike lights available in the market today that have the right level of brightness and motion-sensor technology that can notify other vehicles of your intended direction. 

But should you already have a flashing bike light, make sure that its flashing pattern doesn't exceed 30 flashes per second. According to studies, this is the threshold that triggers seizures the most.

Aside from this, you should see to it that you meet the required brightness according to your environment. Your bike lights should only be 50-60 lumens during the daytime and 80-100 at night for a city road. 

For nighttime riding in the countryside, your bike lights should be 300-400. When you're riding in trails, you should have 600 lumens. 

Any lights that exceed these brightness levels within their indicated environment could already trigger momentary blindness and headache to other people and seizures to those with photosensitive epilepsy.

You can also opt for other trustworthy front lights that use CREE LEDs instead of the usual ones. These CREE LEDs use engineered optics to give you full-road visibility with a low output of brightness. Not only will this reduce the risk of triggering seizures, but it's also energy-saving and cost-efficient.

Thinking about other road users' safety is imperative because your safety is yours too. So the next time you will be shopping for flashing bike lights, keep in mind that there are people around you that may be sensitive to them.