I bought them and didn't notice any difference. I think they may not filter enough, since I don't notice a real change in tint.

What helped me a little bit is changing to a VA panel. They have higher contrast, so you can lower the backlight brightness and still see well.

I bought UV blocking glasses and the purchase has been a life-saver.

Like the GP I had serious eye-strain issues that caused headaches and photosensitivity. The new glasses eliminated the issues almost entirely.

I am not 100% sure though if this is caused by the filter or by my previous pair being really bad.

I've seen those reports as well. I think it will depend on the person, and just because blue light doesn't cause eye disease or not enough studies have been done to test how valid it is does not mean it is not working for some people. It has certainly made a difference to me and several others I know. Just make sure it is genuinely blocking blue light; as I mentioned in another comment, some of these don't actually do what they are advertised to do.