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cataract surgery -- change of bias?

wbs
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Joined: 2010-09-05

I'm taking a break from observing to have my cataracts removed and replaced with toric inserts.  The view through the right eye, which was operated on 3 days ago, is already brighter and more blue (or less yellow) than the left -- there will probably be a change in my personal bias for variables that are more (or less) red than their comparison stars.  When I start reporting observations again, probably in late April, I'm thinking of adding a comment like "first ob after cataract surgery" to the first observation of each star that I have previously observed.

Weather permitting, I may try some one-eyed observations just before the surgery on the left eye, to compare the bias between the old and new lenses.  Is anyone interested in observations like this?  Should they be reported through WebOBS with appropriate comments?

Dick

 

Cataracts and visual zero-point
GTN
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After I had my cataracts removed, the view through my eyes was also much brighter and more colorful, less "yellow".  It was like seeing the world new.  There was no apparent shift in my magnitude estimates after the surgery, but I did gain about a healthy 0.25 mag in limiting magnitude.  I generally work near the magnitude limit where stars appear colorless.

After the surgery, the number and size of floaters gradually increased to the point that they were clearly affecting my magnitude estimates!  Fortunately, surgery got rid of them.  I only had the victrectomy in one eye.  I am waiting a year before having the other eye done.

 

Thom

Evening all- Herse is a
MDAV
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Evening all-

Herse is a paper on post-op eye changes

 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633455/

Cataract and color
HNL
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Joined: 2010-08-02

 This is something I had not thought of currently, But, I had a lens replaced and the current lens is seeing the world blue.  One eye is yellow or clear but, the other is bluish. I thought that it might be a different if you study color of stars.  so, if you want to post this the way you said: That; I think would be a useful subject to study.  Best HNL

Cataract and color observations
wbs
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Joined: 2010-09-05

I'm now recovering from the second cataract surgery (left eye), and my eyes are learning to work together again.  Before the second surgery I had learned to use both eyes together for distance vision, and the color difference had disappeared except under unusual lighting such as mercury vapor or cheap fluorescent lights.  Now that both eyes are done, things look relatively more yellow through the right eye, so I obviously have some unlearning to do.  The right eye used to be dominant, but during the last few years, since the corrected vision in the right eye has become a little worse, the left eye has taken over.

We didn't have photometric skies any of the last few nights before the second surgery, so the only comparison observations I could make were done through thin and variable cirrus, illuminated by light pollution -- with two new car dealerships nearby, we're getting close to 7 on the Bortle scale.

Using my usual 10x50 binoculars, I started looking at VY UMa , which I normally observe by defocusing to minimize the color contrast.  Under these sky conditions I couldn't see VY or the fainter comp star well enough with one eye to judge the relative brightness.

Then I turned to Y CVn, which I usually find hard to observe well because of color differences, using the 49 and 53 comp stars on binocular chart 10807BE.  With the illuminated clouds in the way, the color differences were barely detectable, and I couldn't identify a difference in color from one eye to the other.  With the right eye, the relative brightness of the comp stars and the variable (closer to 49 than to 53) were about the same as with both eyes, but with the left eye the variable and the fainter comp star looked fainter than with the right eye, as compared with the bright comp star, by about 0.1 for the variable and closer to 0.2 for the faint comp star.  I expected that the variable would look relatively brighter through the eye with the dirty yellow filter still in place, but this is definitely not what I observed.

I also tried to judge the limiting magnitude: the 70 comp star was clearly visible with both eyes, easy to glimpse with the right eye, and difficult to glimpse with the left eye.  MY LM is normally around 8 here at the house and 9.5 or better under a really dark sky.  This suggests that the cataract surgery will result in some improvement in limiting magnitude, even where the limit is seriously degraded by light pollution.

None of these observations are going into WebOBS -- I hope to be able to make reportable observations again by the next new moon.

Clear skies and clear eyes,

Dick

And now
gianluca.paone
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Joined: 2013-04-01

Thanks for the interesting report of your experience, and now once again clear sky.

Observing after cataract surgery
wbs
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Joined: 2010-09-05

Now that my vision has stabilized and we finally had a clear night, I got to try observing with binoculars but without glasses for the first time in 50+ years.  It looks like my limit has improved by nearly a whole magnitude since before surgery -- for the first time in a few years, I can solidly glimpse the 8.4 and 8.7 comp stars near Z UMa, which I usually find essential for positive identification.

More good news -- as expected, it is now much easier to observe variables and comp stars that were too close to brighter stars.  On the other hand, the lens inserts have fixed focus, but the overall focus of the eye still shifts a little with head position, so I'm refocusing the binocs more often than before.

The only way I can explain my one-eyed "cataract and color" observations last month is that the darkening of Y CVn and its comp star by the cataract had more effect on the apparent relative magnitude, via the Purkinje effect, than the yellow color of the cataract. 

Dick

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484