Is this serious? i'm flashing my eyes a lot today.. i stay long, long hours on the laptop.

Could be dry eyes: If you mean "blinking"a lot rather than "flashing", it could be that your eyes are dry. People do not blink as much when doing detailed near work or computer. Blinking helps replenish the tear film over your eye. The tears are important for vision and eye health. Try remembering to blink while using the computer or use an artificial tear.

Flashes & floaters: The clear gel that fills eyeball is normally attached to all parts of the inside of the eye. As we get older it can become more liquid (watery) and detaches from the back of the retina causing flashes & floaters. This can indicate a retinal tear. As the retina detaches, change or loss in your side vision is the next symptom. You should see your eye doctor to check the retina.

Flashes: In your age group is most likely visual aura. Related to many factors including lack of sleep. You might want to keep an episode diary looking for triggers. If it doesn't get better get it checked.