I Can See Clearly Now Trivia Quiz

Answer: Cornea

The cornea is the most powerful light-focussing structure in the human eye. It is transparent as there are no blood vessels within it, and very few cells. The cornea contains the most nerves in any human body structure, making it extremely sensitive to pain.

Answer: Iris

The colour of human eyes is determined genetically, though you may not necessarily have the same colour eyes as your parents! Melanin and lipochrome are the two pigments responsible for eye colour, each controlled by a separate gene.

Answer: To stop the eyes becoming sticky with gunk

Tears are also produced to smoothen the (slightly) irregular surface of the cornea, and to destroy any bacteria with enzymes contained in the tear fluid. No-one really knows why our eyes produce tears when we are sad.

Answer: The eyes are different colours

One of the most famous people with heterochromia irides is David Bowie, the UK rock icon. This occurs as a result of genetics, as eyes do not change colour of their own accord!

Answer: True

Colour blindness affects around one in 20 men and 1 in 200 women, and is a hereditary condition. It affects more males than females as the faulty gene which causes colour blindness is carried on the X chromosome. Women would need two faulty X chromosomes to exhibit colour blindness, or one to be a carrier, whereas men only have one X chromosome - if it carries the faulty gene, the man will be colourblind.

Answer: Low blood pressure (Hypotension)

It is quite common for a person with high cholesterol to develop a creamy-coloured ring around the edge of the iris, especially into old age. Whilst diabetes is primarily a disease of the hormonal system, the effects are far reaching and may develop into retinopathy (inflammation of the retina). And yes, sexually transmitted infections (including genital warts) can be transmitted to the eye through contact with the infection! Low blood pressure does not produce any visible effects on the eye, although high blood pressure can damage the retina.

Answer: cones

Rods and cones are so called simply because they are shaped like rods and cones. We use our rods to see in very dim light, though things don't appear colourful as the colour-detecting cones only work in brighter light.

Answer: True

A common topic of debate! Carrots are high in Vitamin A, which is converted to a substance called retinene in the body. Retinene makes up part of the photopigments found on your retina, which detects light. The more photopigments you have, the better your eyes will be at detecting light.

So yes, carrots can help you see better in the dark (unless you otherwise receive enough Vitamin A), but they do not help with any other eye condition or improve eyesight generally.

Answer: They can all be caused by smoking

Smokers have a higher chance of developing any of these eye conditions than non-smokers. People with thyroid problems who also smoke are at a higher risk of developing thyroid eye disease, too.

Answer: Wearing other people's glasses

Ok, so it's a little obvious, but people do it anyway: wearing glasses prescribed for other people is not a good idea. However, eating well, wearing sunglasses in bright sunshine, and not staring at a television or computer screen for too long are all things we should do to protect our precious vision.