General Brightness:
* As bright as the sun.
* As bright as a thousand stars.
* As bright as a diamond.
* As bright as a lighthouse beacon.
* As bright as a summer day.
Specific Types of Brightness:
* As bright as a firefly's glow. (Soft, gentle light)
* As bright as a neon sign. (Intense, colorful light)
* As bright as a laser beam. (Sharp, focused light)
* As bright as a child's smile. (Warm, inviting light)
* As bright as a fresh idea. (Sparkling, innovative light)
You can choose the simile that best fits the context and the type of brightness you want to convey.