Question:
I am headed for cataract surgery. I am 72 and my right eye is down to 20/70,
while my left eye is still 20/35. This is getting a little dicey.
At present I am using bifocals mostly for close up vision, with the
refraction in both eyes about the same. Most of the time my glasses dangle
around my neck.
What is the best way to set the distance for my ocular implant? Does it make
much difference?
Answer:
This is the story of my vison up to now. I hope it can lend some
insight to others facing LASIK and cataract surgery.
I am 69 and have had RK at 58, and now have had cataract surgery in
both eyes. Before RK I had a perscription of -6.5 and --6.0 with a
little astigmatism in one eye due to a collision with a tree branch
some 30 years ago.
After RK my uncorrected vision was 20/20 in both eyes for a few
years, then drifted into farsightedness. At the time of my first
cataract 3 1/2 years ago my correction was about +1,5 left and 1.0
right with some astigmatism (0.5 diopter) left. (RK had attempted to
correct this but failed.) Of course at the time of my RK I had NO
accommodative power left. After the RK I also have the problem that
my vision varies from morning to night. It changes about 2 diopters
farsighted towards nearsightedness. Nobody has satisfactorily
explained this to me, but I believe that it occurs because of internal
pressure in the eye. I have read where this changes throughout the
day. So high pressure in the morning would cause the weakened cornea
to flatten and make me farsighted.
My point in saying all this is that I have had the dubious benefit of
knowing both nearsightedness and farsightedness. Of these I would say
that the farsightedness is worse, because nothing at any distance is
in focus. I would say that if I had a choice, my uncorrected vision
would be set to about -1.0 nearsighted. This would allow you to
perform most day to day activities in a pinch with no glasses at all.
I believe that you could pass the drivers vision test without
correction and you would be able to read most things without glasses
(obviously not comfortably)
My cataract surgeon told me that his normal practice was to set the
IOL power such that it would make me a little nearsighted, which
matched my own predisposition. Since this is not an exact science,
the results on my first eye were such that I need no correction (post
noon) in that eye. The second eye was done about 3 weeks ago and is
still in the process of settling down. At the present time I believe
that that eye is now about 0.5 diopter farsighted. (RATS! I would at
least like for them to be matched!) Only time will tell because for
the first couple of days afterward my, old prescription (+1.5)
diopters) gave me excellent distance. All this complicated by the
variability in my vision. My cataract surgery was also complicated by
the scars left by the RK.
I also have had (just yesterday) the YAG laser on the first eye which
had deteriorated due to the capsule darkening. Still watching this
for side effects.
The debate on monovision I think boils down to this: How is your
binocular vision and how dominant is one eye over the other? If
having one eye patched bugs you no end, then I would think that
monovision is not for you. During the time I was between cataract
surgeries, going without my glasses was disturbing, because of my
dominant eye (the left one which was farsighted). I was beginning to
not be bothered much and if it had been nearsighted instead it could
possibly have been more acceptable.
