People living an eye specialist’s rooms sometimes have great difficulty in focusing if they emerge into bright sunlight. ‘You look like a startled rabbit,’ is a common if unkind comment.
Not all drops gives the eyes that shocked appearance, but some used by doctors before examining patien’s eyes enlarge the pupils and temporarily paralyze them. Normally, pupils adjust like an automatic camera’s lens to admit just the right amount of light. If the light is bright, the pupils contact; if it is dim, they expand.
The eye specialist uses an instrument called an ophthalmoscope to examine the inside of the eye and particularly the retina, the membrane on which images are focused. The ophthalmoscope’s bright light shining directly into the eye would automatically make the pupils contract, closing the windows through which the specialist wants to look.
Sometimes, after an eye examination, you may find your eyelids stained orange. This is because your doctor, in checking for abrasions and ulcers, has inserted a few drops of a harmless orange dye known as fluoresceint. The stain turns conjunctival ulcers yellow; if you have any corneal abrasions or ulcers they appear green under white light, but ultraviolet light makes them brilliantly fluorescent.