lo, I had the same problem. The color contrast was vicious and the fonts were too small. MTE's suggestion is the correct solution to the problem.
To be more specific... in the lower right corner of your log in screen you will find the options button. Before you login, click on this button. It will bring up a dialog window with about 8 different settings that you can change. The background colour is the top most setting. If you click on it in the extreme lower right corner, it will come up with a little dialogue box with three choices...choose the "white" one.
Then, in the second row, you will see fonts. You can then bring up another dialogue box and choose from about 5 different sizes. Play with it a bit, and you will be able to find a setting that gives you less eyestrain.
Don't play with the third or fourth row settings. You need to keep them the same; otherwise your connection will get messed up.
You can also play with the settings for computer use if you need to dedicate more horsepower to TOS. Hope this answers your questions and helps you avoid thick glasses LOL