CAIE IGCSE Biology 14.2.8 Functions of Rods & Cones
Practise comparing rods and cones by sensitivity, night vision, colour vision and response to different light intensities.
- Syllabus
- 2026–2028
- Course
- Biology 0610
Practise comparing rods and cones by sensitivity, night vision, colour vision and response to different light intensities.
The eye is adapted for focusing on near and distant objects.
Fig. 3.1 shows the parts of the eye involved in focusing. The eye is focused on a distant object.

Fig. 3.1
Rods and cones are the receptors in the retina of the eye.
Describe the functions of rods and cones in the eye.
any four from:
rods / cones, are light receptors OR detect / respond / sensitive, to light ;
rods:
sensitive to / function in, light of low intensity OR used for night vision ; provide black and white vision ;
cones:
sensitive to light of high intensity ;
ref. to three different types of cone ;
provide colour vision ;
AVP ;