What brightness? I thought the rods/cones are basically integrators responding to the intensity-time product. The eye does have a huge dynamic range.
Saccades do not affect this, as far as I know. I can see LED car tailights strobing/flickering doing a visual sweep that normally appear to be lit steady.
But 5usec seems wrong, simply way too fast for our physiology - unless you are in a dark room with very bright LED but I've never tried that kind of speed.
The only time I've been into saccades is making emdr machines.