A B737-700 First Officer reported being targeted by a laser on approach to SJC.

Narrative

During the approach to landing at SJC airport; we were established on the ILS to 30L. I saw what appeared to be an extremely bright concentration of green light ahead of the aircraft on the ground left of the extended runway centerline about five miles from the airport. The light appeared on for a few seconds; then extinguished; and once again reappeared. I was not sure what I was visualizing until the second laser attack. I promptly lowered my head so as to avoid any further eye contact with the laser. I promptly notified ATC about the laser event. The Captain who was the pilot flying continued the approach and stated that he saw another green flashing light in the cockpit when we were approximately over the site where I first observed the laser. This was an extremely distracting event which prohibited me from conducting my pilot not flying duties outside of the aircraft. Data should be compiled for areas where frequent attacks occur so that pilots can be ready to take defensive measures before suffering any permanent vision damage.