I’ve always had pretty light-sensitive eyes, but it seems like it could be getting worse lately. But there’s one particular issue that confuses me.
I was trying to take a self-portrait yesterday outdoors. It was an overcast day, not bright at all, and I could look at the ground with both eyes open, but I came to realize that while I was looking level at the camera, I could not possibly open both eyes at the same time. They would immediately, reflexively shut after experiencing acute discomfort. I could hold either eye wide open, but opening them both at the same time resulted in an immediate, uncontrollable reflex to close them.
It occured to me that I probably automatically squint a whole lot with one eye or the other in bright situations and don’t really notice it, but trying to take a picture with both eyes open brought it to my attention.
So if my eyes are merely sensitive, why am I able to keep either of them open individually? Is there some sort of total light gathered by my brain threshold being crossed that’s triggering a reflex?
I have nothing to add but to say that I am the same way and I would curious to hear a good answer for this.
I also experience this and don’t have any light sensitivity problems; I am guessing it has to do with how your brain interprets input from both eyes, as you said. But if so, this means that light entering one eye has to somehow affect the other eye more directly (i.e. it hurts your eye(s) when there is too much light; with both eyes, less light somehow causes the same pain response). Perhaps the pain is indirectly generated by your brain, as opposed to coming from the retina.
I mentioned this in a thread only the other day. Perception of brightness, or at least the pain response, must be happening in the brain. That sounds obvious - all perception happens there - but in this case, there must be some preprocessing happening.
IANANophthalmologist, but could it be a problem with your pupils not contracting properly in response to light?
There are some conditions (no cite, google if you want to) where the pupil/s remain dilated regardless of the ambient light…IIRC, it’s a muscular, not a systemic issue within the eye.
Wouldn’t the pupil contracting thing prevent you from fully opening either eye independently, though? If your eye was too sensitive to the light, it shouldn’t only come into play when you open both eyes together.