All excellent recommendations above. I would also look at bilberry. When I started doing this a few years ago, zowie. Night vision really improved. Known for this. But kept eyes moist and definitely feel a diff in eye health.
Not natural, but I would look intently at alpha lipoic acid. It is a quite remarkable thing. For eye care, diabetics, etc, it prevents glycation. Have known several diabetics who when they engaged in ALA, their eyesight stabilized and improved. Brother in law was full blown diabetic. He was bleeding in his eyes. Panicked, my sweets told him to get thee some Alpha Lipoic Acid. Stubborn old cuss, he did. 30 days later, doctor examined his eyes and reported that there was no sign of further bleeding. 7 years later, needs no glasses. ALA lowers cholesterol dramatically too. It's effect on strengthening the vascular system is well known. Preventing glycation. I would look into this, if it were me, for eye integrity.