Benchmark 4F
The Physical Setting: Motion
Grades 6-8, page 90

Something can be "seen" when light waves emitted or reflected by it enter the eye--just as something can be "heard" when sound waves from it enter the ear.

NSES Content Standard B 
Physical Science: Transfer of energy 
Grades 5-8, page 155 
Light interacts with matter by transmission (including refraction), absorption, or scattering (including reflection). To see an object, light from that object--emitted by or scattered from it--must enter the eye.