Amazon has this LED Book Light by French Bull - LED Book Light - Book Reading Light - LED Reading Light (Black)
For $9.99 was $14.99!
LED reading light features a clip that attaches easily to e-readers and books
Our book light features a neck designed to fully illuminate screen while reducing glare
Portable reading light clip was specially designed to securely attach to all e-readers. Fits Kindle Devices.
Reading light is powered by two CR2032 coin cell batteries (included)
Replacement batteries available on Amazon in bulk for approximately 25 cents/unit