Welcome. My name is ***** ***** would be glad to assist.
Sunlight can affect most photo eyes on garage door openers, there are a number of things that determine why.
Sometimes it happens right off the bat and the sensors have to be re-positioned accordingly to avoid the direct sunlight.
Sometimes it happens only at certain times of the year, such as fall and winter when the leaves are off the trees and the sun is at a different angle in the sky.
If yours have worked fine for many years all the time with no issues, it could be the eye is beginning to loose some function.
Easiest thing to do, is try to position a little differently and clean the eyes at both sides.
Wipe with a damp cloth lightly and that can help to clear the lens so the sun doesnt cause as much distortion.
Other times, a new set is needed.
It is not a definite either or situation, but one that you have to make some changes and see if the issue resolves itself, then replace the eyes as a set.
Might even clear up the problem by swapping location on the eyes, sometimes the receiver cannot see the sending light beam on one side, but has no problem on the other side.
Let me know if anything further will assist on the situation, just reply