We posted this information a few years ago but I thought it was handy advice to reiterate:
Do you have a rock chip that has suddenly begun to spread? Our recent 90+ degree weather is probably the culprit. The warming of the glass by the sun and then the sudden cooling by your air conditioning can cause the chip to spread. If this has happened, replacement may be your only option. If it has not spread, it may be repairable. We generally use the criteria of a quarter. If a quarter will cover everything, then the rock chip is typically repairable. However, if the rock chip is in the drivers direct field of vision, by law we cannot repair it.
If you have a rock chip, call us at the number listed below, we will be happy to discuss the procedure with you.