Ophthalmologist

Ophthalmologists are medical doctors who specialise in eye problems. They can work out what is causing the problem (such as disease or accident). The ophthalmologist can treat some eye problems with medicine or surgery.

The ophthalmologist used a machine to check Marcus' peripheral (side or edge) vision. Marcus had to look into the machine and press a button every time he saw a light. It was a bit like watching the beginning of Star Wars. He also had a test (electroretinogram) to see how well his eyes reacted to light.

Later, the doctor put drops into Marcus' eyes. The drops made his pupils really big and his vision blurry. Then the doctor looked into the back of each eye (retina) to see whether it looked healthy.

The nerves in the retina get excited when light shines on them. They send messages to the brain, which then works out what we are seeing.