Hi doc! every after 3 months i see zigzag sharp light in my eye, for half hour i can't see, n every night in dark room i see like light stars in eyes?

Your symptoms can be: One or two separate issues. Flashes of light seen in a dark room may be due to vitreous pulling the retina. Retinal traction, tears, breaks or even detachments should be evaluated. Lights seen in a zig-zag fashion may be from visual aura known as a 'scintillating scotoma" and is associated with a certain pattern of lights followed by vision obscuration. This as well can be evaluated.

Ocular migraine: Your age a; symptoms suggest this is an ocular migraine. Resulting in flashing lights (scintillating scotoma) ; associated with temporary vision loss (typically one quadrant) ; can be followed by migraine headache. See an eye doctor asap to rule out retinal tear or vitreous traction which could result in vision loss. Don't ignore this, especially if you've had recent trauma, surgery or fam history.