It's easy to figure out what size screen is the best for devkit mod with just easy elementary school math.
Just take of the a cups. Measure the focal lengt in the devkit, which is about an inch. Hold the lens inch above a ruler and measure the distance you're able to see in the best case scenario. Remember to only look forward not the edges.
As a result I got just about 6cm (2.35 inches). Multiply it by 2 and add 5mm for lens separation to achieve the 64mm IPD. 12.5 cm (4.92) is the minimum width of the screen. Divide that by the aspect ratio (of 16:9) and you get the height of the screen 7.03 cm (or 2.77 inches).
You should now be able to calculate the diagonal of the screen √[(7.03^2)+(12.5^2)]=14.34 cm or 5.64 inches.
Personally i rather waste 100 or pixels of that 1080p panel than risk seeing the left and right edges. If you go with the smaller panel instead and see the edges, you can always bring it a one or two millimeters closer to the lenses. That should not make a huge difference in focal lenght, but eliminate the problem of seeing the edges.
If you are talking about 16:10 panels then I need to recalculate
![Geek :geek:](./images/smilies/icon_e_geek.gif)