I have a problem with light-sensitivity of my eyes....
Wow! - So do I.
It runs in my family - I have weak irises, and a lack of retinal pigment
A similar kind of thing to albinism, though not as extreme, and I don't have the white hair/pale skin/red pupils.
A female cousin has no irises at all - Just huge pupils, then the white - she wears contacts with an iris design to cut down the light during daytime.
The effect it has on me is that my pupils don't contract as much as they should, and are far more open at night than is normal - The larger pupil is similar in principle to using a larger telescope to gather more light.
A 'normal' pupil will open to about 7mm diameter, which diminishes with age, and by my age most people are down to a max of about 5mm/5.5mm.
Mine have been measured at 8.5mm diameter, and showing no sign of diminishing yet.
Because light gathering increases by the square of the diameter, this means I'm getting almost 50% more than the average 20yr-old - and at least 2.25x the light-gathering of the average 55+ yr-old.
The combination of almost no retinal pigment and better light-gathering means that I can see MUCH fainter objects in the sky than any of my astronomer buddies - Most are very envious.
It's an accepted astronomy 'fact' that in practical terms, the furthest object visible to the naked eye is the Andromeda galaxy at 2½ million light-years....
Yet I can routinely see M33, the Triangulum galaxy which is almost 3 million light years away, and about a magnitude dimmer than Andromeda.
On really clear nights I've seen Bode's galaxy (M81) a few times - That thing is around 12 million light-years away, and even dimmer than Triangulum.
During the day, I wear sunglasses a LOT more than most, and almost always when driving, especially when the Sun is low in the sky.
