Quadra is potentially epileptogenic, and may also cause migraines and other headaches.
This is an inherent danger of chequered patterns, especially shifting ones like this.
If you have a known history of epilepsy, you would be well advised not to get anywhere near it.
Similarly if you have ever had migraines or other headaches caused by patterns of light, please beware.
If you feel your brain turning to mush while watching Quadra, please discontinue use immediately.
Latent epilepsy is more common than people realise, and I don't want to be responsible for it becoming manifest.