Light reflected from an object enters our eyes through the and .The amount of light entering our eyes is controlled by the . The iris gives the eye its colour.The focuses the light on the at the back of the eye.Nerve in the retina transmit the to the optic which then sends the information to the .
The place where the optic nerve leaves the eye is called a spot. This area does not respond to .

Chemicals in the air enter our nose through our . The chemicals then come into contact with nerve which send the information to the brain via the nerve.
Substances enter our and come into contact with our . The tongue is covered in taste which have receptor . These receptor cells detect the different (salty, sweet, and ) and send the information to the brain.
The skin covers and our whole . The middle of skin, called the , contains nerves and blood . These detect sensations such as , pressure and .