increase the pupillary reflex

improve the consensual pupillary reflex

increase the power of lens accommodation

reduce spherical aberration

decrease the power of lens accommodation

measure hearing sensitiivty using the tuning fork

measure hearing sensitivity relative to a large normative database

quickly tell your subject whether they have a difference in air and bone conduction pathways

measure the duration of hearing with bone conduction versus air conduction

determine if the mastoid bone is the right place to apply stimuli

It's the distance that matches refractive power of the eye to the size of the middle line of text

It's the distance that matches refractive power specifically of the lens to the size of the top line of text

It's the distance that compensates for the decrease in light intensity with distance

It's the distance that matches refractive power of the eye to the size of the top line of text

It's just a convenient distance to use

It allows colour and detail vision which is not present for distant objects

It increases spherical aberration and reduces light saturation

It allows foveal vision

It reduces spherical aberration and increases light saturation

It reduces spherical aberration and light saturation

To enhance the amplification by the middle ear

To bypass the filtering effects of the pinna

To exclude any ambient sounds

To focus sound energy into the ear canal

To take advantage of the amplification by the middle ear

Meissners corpuscles alone

Merkels disks alone

Meissners corpuscles and Merkels disks

Pacinian corpuscles

Pacinian and Meissners corpuscles