
     Eye Glasses In The Computer World 
     by Jim Fulton, Orange Coast IBM PCUG  
 
     Although not an Optometrist, but a user with 30 years of optical 
     engineering experience, I would like  to address Stephen Burnside's 
     quest for help with eyeglasses.  During the 1980s, we have 
     increased the demands on our eyeglasses (and our Optometrists) more 
     than at any time since Ben Franklin introduced bifocals to solve an 
     earlier problem, a broader ability of the population to read. Until 
     recently (except for pilots and a few others) the population sought 
     glasses which allowed them to read books in hand--good focus at 
     12-14 inches --and good distant vision to see stars and ships and 
     shoot ducks.  
     
     More recently, our needs have frequently been to read over a wider 
     range of distances, typically from 12 to 30 inches or more. In my 
     case; I am big and have long arms, work on large drawings and need 
     to read a blackboard from a desk. And--I want to do it all over a 
     field of view which is wider vertically than the range provided by 
     an airline pilot's trifocals.  

     To meet my needs I work closely with, and carefully instruct, my 
     Optometrist on what I want him to provide me in the way of bifocals:  

     1. I tell him I want to read optimally at 16 inches. This typically 
     allows me to read print and video display terminals (VDTs) over a 
     range from about 8 inches to 28 inches thru the reading portion of my 
     glasses.  

     2. I tell him I want to read blackboards, projection TVs and 
     building directories at 5 feet (60 inches). This results in my being 
     able to read well from less than 28 inches (VDT distance) to about 
     12 feet thru the upper portion of my glasses.  

     3. I request the "executive style" lens which provides a wide field 
     of view for the "reading" portion of the lens. The results of these 
     instructions are:   My ability to read effortlessly over a range of 
     8 inches to about 12 feet and a horizontal field of view of about 30 
     degrees. The focus is equally good through either section of the 
     lens at about 24 inches.  

      I can't read the 20:20 line on a standard eye chart at 20 feet 
      (not a big loss) and stars, as well as,  other point objects at 
      great distance are in poor focus at night.  While "processing these 
      words," my pencil draft was at 16 inches and low, my VDT was at 30 
      inches and high, and the hockey game was on at 84 inches and high 
      in my field of view--all in good focus simultaneously, thank you. 
      Even though I touch type, I should point out the keyboard at about 
      16 inches was also in good focus.  

     As a point of information, the Motor Vehicle Department (DMV) asked 
     me to take a quick eye test at about 10 feet on my last visit. The 
     glasses and I worked fine at this distance in daylight.  There is a 
     problem related to item 2 previous; I cannot see well in a dimly lit 
     auditorium at distances of over 20 feet with these glasses. 
     Specifically, I cannot see the graphics projected at the General 
     Meeting or theatrical presentations. For these situations, I use my 
     first conventionally prescribed set of bifocals. 
 
