Q 01/05

What is the term for having irises of two different colours?

A) Heterochromia

B) Anisocoria

C) Albinism

D) Nystagmus

Answer · why

A) Heterochromia

Heterochromia wasn't behind David Bowie's mismatched eyes: a schoolfriend's punch in 1962 left one of his pupils permanently dilated.

Q 02/05

Which part of the eye provides most of its focusing power?

A) The cornea

B) The iris

C) The retina

D) The pupil

Answer · why

A) The cornea

The cornea does about two-thirds of the eye's focusing, which is why laser eye surgery can fix blurry vision by reshaping it.

Q 03/05

Pinpoint pupils are one of the three classic warning signs of an overdose of which kind of drug?

A) Opioids

B) Amphetamines

C) Cocaine

D) MDMA

Answer · why

A) Opioids

Opioids act on the part of the brain that controls breathing, which is what makes an overdose deadly, and the medicine naloxone can prevent death if g...

Q 04/05

Which Impressionist had cataract surgery in 1923?

A) Edgar Degas

B) Claude Monet

C) Pierre-Auguste Renoir

D) Camille Pissarro

Answer · why

B) Claude Monet

Claude Monet put off the operation for years for fear it would worsen his sight, and paintings from his clouded years look blurrier.

Q 05/05

Which photoreceptor cells in the retina work in dim light and see only in shades of grey?

A) Cones

B) Rods

C) Amacrine cells

D) Bipolar cells

Answer · why

B) Rods

Rods are almost absent from the centre of your gaze, which is why a faint star is easier to see when you look slightly to one side of it.