Re: [Leica] Light box user needs dramamine????

[Richard Clompus <rclompus@voicenet.com>]

John McLeod wrote:

<snip>I have had a custom made 19"x25" lightbox for the past few years
(5000 Kelvin rating) with 2 fluorescent tubes and a (non-electronic)
ballast/transformer inside the box.  When I use this thing for more than
about 10 minutes I begin to experience a headache and nausea.  
<snip>

As an optometrist, I would like to render an opinion.  

Given the choice, I would prefer to examine a patient with the above
symptoms.  An ocular health exam and evaluation of any optical
prescriptions used would be helpful.  In many cases, the problem is related
to the brightness of the light box.  Some fluorescent lamps put out quite a
bit of light energy.  When you view them, your pupil has to constrict to
control the amount of light that reaches the retina.  If the light is
bright enough, especially when viewing through a loupe that magnifies the
image and the light intensity, it can cause discomfort or asthenopia.  Ever
notice how close people put their eyes when viewing a slide on a light
table?  There are usually nose prints all over the place.  

I would like to offer two suggestions:

Increase the ambient lighting in the room by turning on more lights so that
the contrast  between the light table and rest of the room isn't as great.
The eyes will have an easier time adapting than going from a dim background
lighting to a bright light table. The second consideration is to replace
the lamps with lower wattage fluorescent lamps.  Sometimes brighter is not
better.  You may be much more comfortable with a lower wattage bulb(s)
which have plenty of illumination for viewing but also permit more
comfortable viewing as well.  Try using a neutral density filter with your
loupe to see if you get a positive response.  Usually fluorescent lamps are
cheap.  It may be worth it to get a weaker bulb(s) and see how you do with
them.

I hope this has been helpful.  It is always difficult to render an opinion
without examining the patient.  I'll be happy to barter a Leica for an eye
exam any day <bg>.

Sincerely,

Richard
- -------------------
Richard Clompus, OD
West Chester, PA, USA





 (no, it's not from the poor 
>quality of my
>>slides).  I think the problem is either the flickering of the tubes 
>(60 Hz) or
>>the ELF radiation from the transformer, but I'm not sure which it is.
>
>Hopefully one of the actual eye doctors will respond:
>
>I would wonder if the adjustable diopter of your loupe is set wrong or 
>perhaps if you need to get your eyes or glasses re-checked for near 
>focus.  About the time I need an updated prescription,  I get headaches 
>from staring at the light table as well as shooting.  (My tennis game 
>slips too)  The other tip is to keep both eyes open while you are 
>looking through the loupe, (as well as a camera) to reduce eye strain.  
>On the other hand I suppose you could try to move the transformer 
>farther away or put a piece of sheet metal over it to help block some 
>of the EMF.
>
>You wouldn't per chance be living on a boat????
>
>In which case I recommend Dramamine and Tylenol  ; - )
>
>Duane
>
>
>