Arwen, photochromic lenses (“Transitions” is a technology version registered by
Transitions Optical) glasses are a good idea. They help to cut the glare while
out in bright sunlight and adjust fairly quickly to moving into shade. The only
real problem can be that they are not fully effective for driving as they don’t
achieve their full darkness in the vehicle, however, it is possible to get
‘driving’ glasses with a basic tint and which are also photochromic in full
sun. Transitions Optical claim their Transitions lenses also block 100% of UV
rays but UV filter coatings can be added to any lens for a reasonable price.
Glasses used in full sun should have the UV filter treatment as a matter of
course.
And birdwatchers who spend a lot of time in the sun should consider wearing UV
filter treated sunglasses to protect their eyes. Extended exposure to UV light
is a major cause of cataracts.
There should be no real problem with reduced light through photochromic lenses
while using binoculars as the area covered by the binos will revert to clear
fairly quickly. It is quite fascinating to stand in full sun and hold your
binoculars to your photochromic lenses for a short while and then check the
circle of almost clear lens where the binos had been. Of course, there is a
short ‘transition’ time so any one in the habit of only taking glances through
their binoculars may be affected more by the momentary drop in light
transmission through the binos. However, the pupil of the eye adjusts fairly
quickly to variations in light levels.
One thing I have wondered about is using yellow-tinted glasses such as some
cricketers use. Apparently the yellow tint enhances ‘contrast” thus making some
objects easier to see.
Has any one had experience with yellow-tinted glasses?
Bob Inglis
Sandstone Point
Qld
From: Arwen B. Ximenes
Sent: Sunday, July 22, 2012 7:40 AM
To: ; ;
; ; ;
; ; ;
;
Subject: birding and glasses (and contact lenses now)
Hi again,
sorry I haven't had a chance to reply since my last email, thanks for all the
additional responses!!!
well, I've been doing some research and I'm leaning towards trialling contacts
(I also found the contact lenses thread) - mostly because of all the issues
with glasses - I don't want to have to switch between normal glasses and
sunnies, and I don't like the idea of having to look through the frames all the
time, then there's the problem with rain/steam/spray, getting used to
glasses+bins, etc.
My research so far indicates the glasses lenses that would be most suitable for
birding are the new (expensive) Japanese freeform lenses - these are multifocal
but with a wider distance field as I understand it - perfect for birdwatching
and also easier to get used to apparently. I thought it worth mentioning for
those out there who said they wanted a wider field of view. I might need to
wait for these, another reason to try contacts.
I am interested in Judith's suggestion of putting one contact lense in the
dominant eye - I didn't discuss this with the optometrist though as I was
really thinking glasses at that stage, but will do so. Apparently you can also
get multifocal contacts now - I'm not sure about those, or how they work.
I do have a question - I thought it odd that the optometrist didn't think there
was a problem using bins with sunglasses (i.e. prescription sunnies) - surely
you need light to see through the bins? Both people I talked to in the shop,
one being the optometrist, were convinced sunnies would hardly make any
difference.
My heartfelt thanks again to everyone who shared their experiences and ideas,
there were many points I would not have thought of.
I'll keep you posted.
Arwen
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