Vertical Lines Monitor

Sounds like you have a defective display, so if you're still within the exchange period with the reseller, that would be the ideal way of taking care of it. If you're beyond that point, but still within the display's warranty period, make an RMA claim. If you're past both of those, then start looking for a new monitor.

yes, i agree.. i think your screen got dead pixels, the options above are your choices and im gonna add one more option, you can replace the screen from a benq service centre, it will definitely be cheaper than getting a new monitor.. i.e. if all the above options are not possible, but before you do anything, try hooking up ur monitor to a different PC or laptop to see whether its the monitor which is at fault, coz it could just be a Cable/ DVI adapter problem

Uhhh, the above people are wrong.

It's an LED lit screen isn't it?
BenQ is an off brand, therefore it's a case of, you get what you pay for.

What you're seeing is vertical blocks, right?
They are lighter on one side of the screen and progressively get darker as they go towards the other side of the screen, right?

What the issue is is the screen is LED Edge-lit. Meaning that there is an LED strip running down one side of the screen, in my experience usually the right side, that lights up the whole screen. To adequately distribute the light, there is a light diffusion layer that is supposed to evenly distribute the light to the other side. On lower quality displays, you see each part of the diffusion layer distributing the light on the screen in blocks. This is usually only apparent in dark or low lit graphical content.

i bought it just a week ago..

and just as you said and i also said in my post that i see that vertical blocks
of lighter and little darker shaded flowing from bottom to top vertically.

I see it more clearly when i go in darker backgrounds in game, but when i do usual stuff and when i am in bright zone i see less of this.

so please confirm is it the quality of monitor or should i go for exchange as people have told above..its just a week old maybe i can get it exchanges or
call in for warranty but for that i need to be sure that its sure a monitor defect or just what i ought to get for what i bought..