My right eye has not been really functioning since 1982, when I was 17.
I wore cataract first in May 1982 while I frequently hit my right eye due to the strong itchiness caused by chronic skin allergy. Eventually I lost my sight from the right eye, and after a few eye check the retina detachment was discovered. I was immediately thrown into a hospital room, locked onto the bed with keeping my face up against the gravity (so that the gravitational force helped preventing further detachment) for three weeks, in June 1982. It was an awful experience for a young teenage boy.
I had to have another surgery on September 1982 because of the unfixed detachment again. Later I had another surgery to fix the squint in 1983, caused by the previous surgeries. And finally in March 1986, the swollen and white-colored lens cell (yes, the lens is a single cell) which had lost the transparency in my right eye finally got taken away.
Fortunately, the retina (not the Apple's high-resolution display) in my right eye is mostly functioning OK, though I really can't read anything with it, and I can no longer accurately identify the 3D depth any more. I usually ignore the sight coming from my right eye other than the level of the light.
I've been with the usability problem caused by the broken right eye for many years, long before I started professional programming. Fortunately I've learned how things get large and small when their distance changes, so I can sway to avoid getting hit from most of the things. I still can enjoy 3D movies, though I won't accurately focus anymore.
Things coming towards me from the right side, however, are hard to recognize. I've stopped operating any vehicles including bicycles; I don't have a driver's license either. You don't want to get into a trouble which you can easily expect, especially where the driver's seat is on the left side of the car, like in the USA or Canada. Japan is not, but that doesn't alleviate the problem.
During the age of 80x25 character terminals when DEC VT100 or VT220 terminals were popular in 1980s, my right eye disability didn't cause much trouble, because the whole screen fit very well in the visual space I could recognize. Even in the age of where 14" or 17" CRT or LCD displays, where the default aspect radio was 4:3 or 5:4, I didn't have much problem. I've written a lot of document and many pieces of code; fortunately none of them mandated me to tackle the three-dimensional loss of perception.
I have a few problems regarding my sight disability since the beginning of the 21st century, unfortunately. One of them is the color design; most web sites choose white as the background color, which interferes the black foreground characters I read. I try to choose darker background colors and brighter foreground colors as possible, but not all web applications allow to do so.
Another one of the 21st century problems is the change of default aspect ratio of the screen to 16:9; this is too wide for my rather narrow sight space. If you are watching a movie this wouldn't be a problem. I welcome high-resolution displays with crispier pixels and accurate positions. But when you write a text, this will be a serious problem, because you can't see everything at once. I always choose narrower horizontal size to keep the screen in my left eye's sight range.
So far I can manage the environmental change of computing in the past 31 years. I expect, however, the future computing models, including those require wearing glasses or assume three-dimensional recognition ability, may eventually reject me from the cutting edge of computing. Maybe I can ask Google to make a special Google Glass to compensate the loss of my right eye's lens and focus directly into my right eye's retina, with proper size adjustment so that I can see the things in two eyes again.
And I can assure everyone that you can write the code with sight disabilities; I know a professional programmer who has completely lost the sight too.
(Thanks Tyler Hannan, who suggested me to write this. I had been hesitating to write about my weakness on the web, but I thought this would be helpful to others.)