Could optometry explain why UFOs can be hard to photograph or hard for some to see?

So I’ve been reading up a little on vision and the electromagnetic spectrum, and I’ve learned two very interesting facts:

There seems to be some inter-individual variability in people’s ability to see light at the edges of the visible spectrum, and some people can apparently see infrared or ultraviolet frequencies that are invisible to most people. (Anyone who has had their lenses removed can also see more UV.)

Scientists have demonstrated experimentally that infrared light can become visible to anyone (appearing as green, supposedly) if it is pulsed rapidly – presumably to increase the energy imparted on the photoreceptor. It’s unclear to me whether the same could apply to microwaves (which have also been associated with UFOs) with a more rapid pulse.

This has led me to suspect two things:

1) The reason why some people see UFOs that others can’t see is that the objects are sometimes only emitting visible EM radiation at wavelengths that most people can’t see.

2) The reason why some photos of UFOs turn out so poorly is that the camera is filtering out wavelengths that humans normally can’t see, but the person taking the picture may still see them – either due to a rare ability or due to the radiation being pulsed rapidly.

Does anybody have any thoughts on this? And has this been proposed (or debunked) in ufology before? Maybe Garry Nolan would know?