Where it is
The cornea is the clear dome at the front of the eye. The lens sits behind the iris, held by suspensory ligaments attached to the ciliary body.
What it does
The cornea provides most of the focusing power. The lens changes shape for near vision (accommodation); it becomes stiffer with age (presbyopia).
Clinical relevance
- A cloudy lens is a cataract and is treated by lens replacement.
- Corneal abrasions are very painful; contact lens wearers are at higher risk of infection.
- The corneal (blink) reflex tests cranial nerves V and VII.
Nursing focus
- For unconscious clients, protect the cornea with lubricating drops and keep the eyelids closed to prevent abrasion.