Here is the answer from Pinlock
Dear Rae,
Thank you for contacting Pinlock and your interest in our product!
A Pinlock lens can be used during night time. On the packaging of the lens we added a ‘daytime use only’ advice because during dusk, night and dawn, we cannot guarantee the levels of opacity yet. During low-light conditions, light can bounce between the lens and the visor, causing lights to appear double. We would advise weighing the pros and cons of your Pinlock usage in low-light conditions.
We hope this information has been helpful. If you have any further questions please feel free to contact us.
Kind regards,
Vianne