Re: trifocals

[Ian White <Ian -at- IFWTECH -dot- DEMON -dot- CO -dot- UK>]

Kat Nagel/MasterWork <katnagel -at- eznet -dot- net> wrote in reply to Cathy Luther:

:      Anybody out there gone with tri-focals?  I jut got
:      tired of tired eyes, tired neck, tired everything.....

: Yes.  I tried standard trifocals, but the little lines drove me nuts.

: Now I have something called 'progressive lenses'.  No little lines.
: Distance prescription on top.  Reading presecription on the bottom.
: Mid-distance in the middle (state the obvious, Kat; waste bandwidth; see if
: anybody notices). Full width of the lens for each focal state, and gradual
: transitions between them.

: It took me about 2 weeks to get the hang of it --- where to position my
: head/neck for each activity --- but now I love them.  Except when I'm
: walking downstairs.  Maybe I should get quadrifocals, with a thin strip of
: distance-focus on the bottom so I can see my feet.

I find the 'progressive' or 'varifocal' lenses useful for a wide
variety of activities - but not for screen-gazing. The vertical
field of view is not wide enough, so there's no position of the
head that brings the whole screeen into focus. Also there's a
narrowing of the undistorted horizontal field of view at
intermediate distances.

A pair of conventional single-focus spectacles prescribed for the
distance of the screen is much more effective, and allows me to
see the whole screen in focus by moving only my eyeballs.

On the other hand the varifocals are a godsend for 'mixed'
activities and I wouldn't ever leave home without them.

Jumping between discussions, I strongly agree with other writers
who find it much more comfortable to place the monitor directly
on the desk - it greatly reduces neck strain. My eyes are level
with the top of the screen when the chair is adjusted so that my
feet rest on the floor and thighs are horizontal. Working onward
from those fixed points, the keyboard is on a slide-out shelf,
about 2 inches below desk level, which leaves the wrists straight
when typing or using the mouse The arms of the chair provide extra
support when needed.

It helps to build your own desk :-) but the important thing is
to experiment and change the furniture if necessary.

Every body's different, and everybody has the need - and the right -
to be physically comfortable at work.


--
Ian White                    | IFW Technical Services, Abingdon, England
                             | Clear English for high-technology companies
ian -at- ifwtech -dot- demon -dot- co -dot- uk      | Tel/fax (0 / +44) 1235 535981