In many areas, you're required to have a windscreen on your car that is not damaged in any way; failing to do this can result in very expensive fines, and can also mean that you're not truly safe when on the road. To ensure you keep your car in good repair and understand the importance of a good windscreen, note a few common misconceptions many people have about this car part and its overall function, and about repairing it when it's damaged.
Damaged windscreens and your vision
It is true that a crack, chip, or other such damage to a windscreen can get in the way of your vision, but a windscreen is more important to your safety than you may realize. That windscreen provides support to the roof of the car, keeping it from collapsing in the event of a rollover accident. A windscreen stops you from flying out of the car in the event of a collision, also reducing your risk of catastrophic injury.
It's important that you understand these functions of a windscreen, as one that is chipped, cracked, or otherwise damaged is compromised, and may break from a roof collapse or from an impact. This can compromise your safety and even lead to a fatality during an accident.
DIY repair kits
Many DIY repair kits that contain gels or other such substances won't fill in a large crack or chip in the windscreen, and won't hold that repair job very securely. It may also take some skill to actually apply the gel or other material and ensure that it reaches every crack, chip, and pitted area.
Also, you need to avoid the mistake of applying the material during certain weather conditions, or driving the vehicle before it's properly set. Having a professional manage the repair of your windscreen is always the better option, for these reasons.
Repairing chips and cracks
Unfortunately it's simply not true that all chips and cracks can be repaired with gel or other fillers, as some chips are too large and may have penetrated both sides of the window, so that the gel has nothing to adhere to while it dries. Note, too, that the gel or other filler used for minor repairs is not as strong as the glass itself, so using too much of it can compromise the overall strength of the windscreen. As said, this can increase the risk of it outright breaking during a collision and, in turn, increase you risk of a serious injury.