The eye distance doesn't actually change the clipping distance it just changes how far away objects appear to be. Assume you have a model in which ten pixels represent a foot. You create a box that has a height of 50 a width of 50 and a depth of 50. If you half the eye distance and make it 250 then your box will appear to have a height of 50 a width of 50 and a depth of 100. When you changed the eye distance you changed your model along only the z axis to be five pixels per foot. This changes your box to be rectangular. You can get around this by halving your depth. By changing the eye distance you can make objects look like they are disappearing\appearing farther away but they disappear\appear the same number of pixels away. This works fine unless you are concerned about the resolution of your game which I am. There is a similar property in each 3D box you create called Rise Scale. "Effects how the Z units are scaled. eg: A depth of 20 will actually be sixty four if the scale is 3.2." If you look at the bottom of your properties bar with Rise Scale selected this is the message you will see. I had the idea to use both eye distance and rise scale combined to make them appear to be farther away when they disappeared without losing any resolution but was not able to get it to work. I then experimented with Rise Scale alone and found it did not distort the proportions of the box but only the placement. I saw that with several boxes with different rise scale settings they all disappeared the same distance away from the screen. ie. They were all the same width on the screen when they disappeared. If any one knows how to change the actual clipping distance or how to use eye distance to make the clipping distance look farther away without losing resolution then please tell me.
-----------------------------------------------------------------------------------------------------------------
Edit: I went and messed around with the eye distance some more and found that it does change the number of pixels from the screen that objects disappear but I couldn't get the distance to be more than eleven thousand pixels. If you are doing 20 pixels per foot that is only five hundred feet away. This means if you have something in your game around thirty feet tall or so it will disappear while still quite large on the screen. Changing the eye distance does affect objects like I said earlier so I still have a problem with resolution.