Sorry to be pedantic but Angel Eyes are completely different !
Angel Eyes are the yellow rings you see as the parking lights on Beemers for example. A lot of people have modded MKIV headlights to include them as yellow rings around the driving light.
HID's are.........
FAQ about HID kits:
What is HID?
HID stands for High Intensity Discharge. It refers to lighting technology that relies on an electrical charge to ignite xenon gas contained in a sealed bulb. The technology of HID automotive lamps is similar to that of common vapor-filled street lamps. HID lighting doesn't have a filament but instead creates light by igniting an arc between two electrodes. HID lights get their name from the intense white light produced by the electrical discharge. HID lamps are also called xenon lamps, referring to a gas inside the lamps. HID general lighting has been used for years in sports arenas and stadiums around the country.
Why HID?
Some auto experts cite the almost complete darkness on isolated highways as a reason for why HID lighting is becoming popular. HID lights promote safety by providing a better overall view of the roadway and the ability to see upcoming objects quickly and more clearly. For example, road signs and objects on the road are easier to see when illuminated by HID headlights.
How is HID different?
HID lighting provides about three times the light output of standard halogen headlights while using less energy. HID lights are designed to last up to ten times longer than standard halogen lamps.
What about HID's color?
The color of the light source is expressed as its color temperature. As the color temperature increases, the color of the light moves from yellow to white to blue-white. HID headlights provide light at a higher color temperature than standard halogen headlights, which gives them a crisp white appearance. More K does not mean it is brighter.
Are HID headlights better, brighter, safer?
HID lighting provides the brightest illumination available. The more intense, higher color temperature light results in three times the output of standard halogen lighting, which means improved peripheral vision and enhanced down-road visibility. The end result is safer driving for everyone on the road.
What sizes do HID's come in?
We have the main 8 sizes car headlights are designed for: H1 H3 H4 H7 9004 9005 9006 9007
Why is it so expensive
HIDs are more involved than normal bulbs. They come with ballasts, gas bulbs, and custom wiring. The cost to manufacture these items adds up.