headaches on longhaul daylight flights

[747pilot747]

Hi,

I'm a longhaul pilot and I tend to get headaches that originiate right behind the eyes. I almost always get them on daylight flights and cannot remember ever having one on a night flight.

I wear spectacles to correct a mild case of myopia and astigmatism but I generally take them off during the cruise. I wear sunglasses if it's bright outside. I've been flying longhaul for 5 years now and I think I've always had this problem. Any ideas? I'll mention it to my AME on my next visit but maybe someone out there has some experience with this.

Thanks.

[FlamantRose]

Hello,

During my childhood, tears would come to my eyes each time it was too bright outside. No problems at night. So I wore dark glasses (1950 thru 1960) during daytime. Then it was discovered that I suffered astigmatism. So correct spectacles for the astigmatism but also very dark glasses. And when I say dark I do mean dark, almost black. No more headaches and no more crying in daylight. In the 80's when my eyesight started tumbling down I was issued stectacles with all the adequat corrections and I started diminishing the darkness of the glasses. I now still wear tinted glasses but only with a very faint tint, something like 25% (no where near what I used to wear).
I don't need sunglasses anymore since roughly 15 years.

[DX Wombat]

Are you using wrap-around sunglasses? These stop harmful rays getting in through the side of the eyeball and should be worn both inside the aircraft and outside. Is the flightdeck warmer during daylight flights or do you feel warmer from the direct action of the sun? If so, you may be mildly dehydrated so try increasing your fluid intake. You have already said that you will mention it to your AME and that is the most sensible idea. An eye test wouldn't go amiss either.

[Desert185]

The windshields aren't coated to block UV. Wear UV-block glasses, use the sunshades to prevent squinting and drink plenty of water. If you aren't peeing at least every three hours, you're dehydrated.

I also wore a long-sleeve, cruise shirt to keep the damaging UV off my arms. When I retired, the left sleeve was noticeably more faded that the right sleeve (NOPAC flying westbound during the day). At the very least wear UV blocking sunscreen if you're going to do it for decades.

Ex-long haul guy.

[Loose rivets]

Odd thing this. Ultra Violet light ( of any significant energy ) does not get re-radiated from the opposite surface of the glass. So sure of this was Richard Feynman, that he looked at the first atomic blast through a lorry windscreen. However, he ended up throwing himself to the floor of the cab with a huge mauve blotch on his vision.

He did know a thing or two. High energy UV can not be reproduced by the atomic structure of glass, but of course, a great deal of lower frequency photons do appear to pass through unhindered.

Not only does the glass seem to act as a filter, but it also has layers of other stuff in it. Gold would be a partial stopper of energy, and reflect a proportion of the light in the first place.

Anyway, UV at a wavelength a tad either side of 3,000 angstrom is the (ho ho ) hot-spot, and huge amounts of light can still give you a tan through glass, but the really critical range is in a bracket that's seemingly 'filtered.'

The process of temporarily raising the energy level of an electron in the glass, seems to not only delay the light, but alter its total energy - despite the individual photon being an exact duplicate in frequency and angle.