Ten years ago I happened to discover a potential of 0.25 VAC between
> the grounding electrode under my electrical entrance and the one under
> my telephone entrance. To protect my computer from lightning, I
> bonded them with twenty feet of wire. It paid off in 1998 when
> lightning struck a tree thirty feet from my electrical entrance. I
> was online and suffered no damage.
> A telco man restored service by replacing a fuse on the utility pole.
> When I asked the company's policy on bonding, he beat around the bush
> twenty minutes before saying the electrical code required it but the
> telco didn't like it because they would have to replace more fuses.
> Neighbors went online five years ago. Each time they've lost a modem
> or surge protector, they have asked me for an explanation and I've
> told them ground surges will keep getting them until they clamp a wire
> between their phone and power electrodes. They have always ignored my > advice.
> I was online Monday during a quiet rain when lightning hit my chimney,
> blowing masonry and shingles sixty feet in all directions. My screen
> froze with a weird tint, but things were fine when I restarted.
That weird tint was the monitor being influenced by the magnetic field generated by the lightning strike. Sort of like moving a large speaker near the monitor, except in this case it was probably several orders of magnitude higher.
Your monitor probably degausses when powered on so that's why it cleared.