IGCSE Biology glossary
Cornea
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
The transparent front layer of the eye that refracts (bends) light entering the eye. The cornea provides most of the eye's optical power, bending light rays so they begin to focus on the retina.
What to include in an exam answer
The cornea refracts light; the lens does fine focusing. State that the cornea is transparent to allow light through, and curved to refract light. Do not confuse it with the sclera (which is opaque and white).
Example in context
State the function of the cornea (1 mark): The cornea refracts (bends) light as it enters the eye, helping to focus it onto the retina.
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