The Pelican-- The Aging Birder

By Linda St-Cyr

Disclaimer – I am not a doctor.  These are just my own experiences.  I am 72 years old.

Hearing Aids – Birding convinced me to get hearing aids. I went on a walk where the leader (Ned Bohman from GBBO, no slouch at birding!) heard 29 Rock Wrens. I heard just ONE Rock Wren. The very next day, I made an appointment at Costco to get hearing aids.  
My hearing aids interface with a phone app, so right before I go on a walk, I boost the high frequencies via the frequency plot in my phone app. My favorite high-frequency birds are Bushtits. To me, they sound like a bunch of tinkling bells. I guess I must enjoy my hearing aids because if I go on a walk and realize that I’ve forgotten to put them on, I get really annoyed with myself. The “voice recognition” setting in the phone app also helps me in the book club to hear what is being said. I still use subtitles for movies & TV, though. Hearing aids haven’t helped much there.

Cataract Operation – I just scheduled, so I can’t report on results, just the research.  There seem to be many things to consider, but most resolve to choosing the number of focal points for the replacement lenses. There is an option to combine 2 or 3 focal lengths; in other words, you can have a lens implanted that would allow you to 1) see at distance and 2) read closeup and 3) do middle-focus things (like working on computers and reading music), all without glasses. In a way, it would resemble bifocals or trifocals, EXCEPT the images are superimposed upon each other, not separated as they are in glasses. Your brain handles the superposition to select the image that is in focus.  

I rejected this because it splits the incoming light to service each of these goals.  Multiple focal distances means that when birding, not all of the light is being focused for the bird’s distance. They say that this is most noticeable at night when lights (e.g. car headlights) seem to have halos around them. The halos exist because some of the light is not focused for distance vision, and the unfocused light creates the halo. Since sunlight on a sunny day is usually way in excess of what we need in order to see well, perhaps it makes little difference to sacrifice some of the incoming daylight to the focal lengths that are not needed when birding. But I found one mention attributed to a doctor that “visual acuity and contrast would be less than with a single focus lens” which would be consistent with sacrificing some light. Some terms for the multifocus lenses are “continuous focus IOL” (Intraocular Lens) or “extended depth of focus IOL.” I also noticed reports that depth perception can be affected by these lenses, I think probably because the brain is choosing between objects that simultaneously appear to be in focus but are at different distances.

All of the people I spoke with who had undergone cataract surgery chose 1 focal length, a distant focal length. Then glasses would be used for reading or working on the computer. Birding would only require glasses perhaps for using eBird or referencing written bird information like Merlin provides. Otherwise you could go birding with just your binoculars, no glasses.

One way to research your own personal preferences is to get some disposable contact lenses.  (The new disposables are very comfortable; I didn’t require any adjustment at all.) That approximates what you would experience after a cataract operation that was done for a single distant focal length. Also, for example, I briefly considered doing one eye for distance and one for close reading, and I simulated this, too, with contacts; I left one contact in and one contact out (since I am near-sighted, this approximated one distance eye and one reading eye).  Having different focal lengths in each eye wouldn’t impact birding while using binoculars because each eye of the binoculars can be adjusted separately. The binoculars worked perfectly for both eyes after I readjusted them.  However, that means that I was scouting for birds with only one eye (the one that had a contact lens). The other eye was useless for scouting since it is extremely near-sighted. I didn’t like that!   

Using contact lenses also lets you know how annoying you will find it to be to carry around reading glasses and middle-focus glasses if you opt for single focus (distant) in your cataract operation. If that’s a deal-breaker, you’re back to considering the lenses with 2 or 3 built-in focal lengths. By using contact lenses, I found that I can usually decipher enough of the eBird screen to record my birds without resorting to reading glasses, probably because I have the eBird list somewhat memorized, but I definitely checked the list at home with my reading glasses on before submitting. Be advised that multiple focal lengths add significant cost to the operation. Likewise, corrections for astigmatism, if your eyes need that. Astigmatism can be determined from your glasses prescription.

Contact lenses are also nice if you find yourself outside on a slightly rainy day.  Birding doesn’t have to be cancelled when it rains—after all, the birds still have to go out and find something to eat!

Oddly, I didn’t find any birder opinions on multifocal lenses on the internet. But I did find one birder who wrote about her cataract experience (she got the standard one-focal-distance lenses), and included some fascinating photos to show how her cataracts changed the colors she saw:
https://blog.lauraerickson.com/2019/12/i-can-see-clearly-now.html

​One thing she mentions is that by having the cataracts removed and birding without glasses, she can use the binocular’s eyecups to block peripheral light. If you use the link above, you will find other well-written articles listed along the right hand side that detail her full cataract experience, including the operation.   

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