Simplify the following text for a Grade 6 native English-speaking person.
Original: Rod cells , or rods , are photoreceptor cells in the retina of the eye that can function in less intense light than can the other type of visual photoreceptor , cone cells .
Simplified: Rod cells are one of two types of photoreceptor cells that can be found in the retina of the eyes of humans , as well as other animals . The other type are the cone cells .