The overdrive of your eyes and eyes muscle will definitely cause the dazzling. The reason is, 1. The fatigue of brain cells and relative nerves system will be hurt after overload labor. 2. Lack of nutrients supplement will need food and nourishing. 3. Lack of body physical exercise will lead you lack of oxygen circulation. 4. Even machine will need repair and lubrication, how about your body? 5. The eyes system are connected with your brain, when they fell into the strike condition, you will feel blank of your mind and eyes. It's not strange to get this feeling, but do not worry, it the relax and supplement come over, this symptom will disappear soon.
Well, it seems that you are too anxious about your dizzy feeling, as a matter of fact, there`re nothing to be worried about. Maybe it`s just because you had a whole day`s work, and everyone in that situation will experience uncomfortable feelings, don`t you think so? So, feeling dizzy when laying in bed is supposed to be normal, nothing special. However, you might also keep an eye on your condition and see if it doesn`t get better. If you constantly have the same feeling, you can go and see a doctor. Serious diseases are usually too hard to be found.
After a long time work before the computer, your eyes muscles may get intense and tired. Once you lay down and close your eyes, the eye muscles will suddenly take a relax. That is why you feel dizzy. You should adapt your eyes at an appropriate speed. Or else, your eyes will feel dry and not comfortable which may arouse other eye diseases.