I just read again a book I read for 20 + years ago..
Melatonin - the key of life
Walter Pierpaoli, M.D., Ph.D.
The reversal of aging with melatonin

There is a chapter there about vision, where he writes;
"I have firsthand knowledge of one case in which melatonin completely reversed a serious eye disorder that primarily afflicts older people,
and often leads to partial or even total blindness. Macular degeneration is a
progressive disease that slowly destroys the macula, a part of the retina that
is responsible for central vision. This is the kind of vision that is required
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for activities such as reading fine print, writing, or driving a car. Blind spots
appear in the field of vision, and as the disease advances the blind spot can
grow, although some peripheral vision usually remains.
Macular degeneration can occur on its own, or it can develop after surgery for a detached retina, another common eye problem of aging
in which the retina becomes separated from its attachment. The retina is
held in place by the pressure exerted by the fluid of the eye, but as we age
the pressure can drop and the retina can easily become displaced and float
around the eye. If this happens, the retina must be reattached by laser surgery. Even after the surgery, there is a risk that the retina will detach again.
In fact, one of my friends in Milan had to have this surgery several times,
and unfortunately, even though the surgery was successful, he then began
to develop macular degeneration.
In this case, the loss of vision was a particularly devastating blow
to my friend, who as a teacher and a scholar was always either reading or
writing, two activities that would be sharply curtained by macular degeneration. In preparations for the dark days ahead, he had already begun to
put his favorite books and papers on tape. At my suggestion, several years
ago my friend began taking melatonin. After a few weeks, he reported that
he had begun to notice a gradual change for the better is his vision. Within
a few months, he said that his vision had returned. Wondering whether he
was experiencing some kind of placebo effect, I declined to take his word
for it. His ophthalmologist and later other doctors verified my friend’s
claim, confirming that he had indeed been cured and that this was the first
time they had ever seen macular degeneration heal itself. Although the
doctors did not quite believe that melatonin was the reason, they conceded they could offer no other rational explanation. Neither can I. Based on
this event, clinical trials are now planned to determine whether melatonin
could be an effective treatment for macular degeneration. Preliminary but
strikingly positive results are reported in the Appendix.
I do not know precisely why melatonin worked so well for my
friend, but I suspect that it may have exerted more than one action in his
eyes. Melatonin may affect fluid formation, and thus normalize fluid pressure within the eyes, which in turn would protect against diseases such as
macular degeneration. I also theorize that melatonin’s capacity as an antioxidant may protect the macula from further damage. Melatonin may
also affect the light-sensitive cells of the eyes in ways that we still do not
understand. In the case of macular degeneration, melatonin’s positive ef
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fect could also be related to the melatonin/zinc connection. As I have said,
studies show that older people are often zinc-deficient and that melatonin
normalizes zinc levels in both animals and humans. Zinc, in turn, may
play an important role in the prevention of macular degeneration or retinal separation. One study performed at Louisiana State University Medical Center tested the effect of zinc on macular degeneration. In this study,
patients with macular degeneration were either given zinc supplements or
a placebo. The patients taking the supplements showed significantly less
vision loss than those taking the placebo.
Although we don’t’ have the definite proof yet, these studies and my
own experience have fully convinced me that melatonin can help preserve
vision, and this deserves active controlled study."

So, perhaps he should give Melatonin a try? It's natural, it's not expensive and it helps with many other problems as well...

Forever Grateful, BUT, sometimes pissed of. wink
Trygve "Leo" Larsen
BiaB 2020, Windows 8.1, Intel Core i5 CPU, 270GHz, 32 Gb RAM
My OLD tracks on Soundcloud; https://soundcloud.com/trygve-larsen My NEW is unpublished
The Universe = Uni-verse ie one song.