Replacing fluorescent light

[swampydrill]

My fluorescent light takes forever to come on, when I say forever, it must be 10 sec. Is this a sign that it is on its way out. Has been there a long time so maybe change the whole light out, I see new ones have a Prismatic Diffuser, what on earth is that??????

 

[OwainDIYer]

the frosted plastic cover over the tube

 

[PrenticeBoyofDerry]

I see new ones have a Prismatic Diffuser, what on earth is that??????

As above it is the the plastic cover that is attached over the tube/lamp.
diffuser images

Common fault with fluorescent fittings are not only tube failure but also the starters. If changing the starter check you install the correct rated one.