Chapter: 3 Movement in & out of Cells

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Focus light .

• For the brain to see a clear image, there must be a clear image focused on the retina.
• Light rays must be bent so that they focus exactly onto the retina.
• Bending light rays is called refraction.
• Most refraction of the light entering the eye is done by the cornea.
• The lens makes fine adjustments.

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Adjusting the focus

• Not all light rays need bending by the same amount to focus them onto the retina .
• Light rays coming from an object in the distance are only diverging slightly.
• They do not need much bending.

Ziad ahmed – IGCSE-AS-A-Level-IB Biology Teacher WhatsApp: [phone]

Adjusting the focus

Ziad ahmed – IGCSE-AS-A-Level-IB Biology Teacher WhatsApp: [phone]