why measure vision? 1.1

Question 1

what do optometrists do ?

Answer 1

measure sight and a number of other features related to it

Question 2

what is vision?

Answer 2

perception of differences in the external world resulting from stimulation of the retina by light

Question 3

what does vision include?

Answer 3

light changes
colour
shape
position

Question 4

what are some types of vision?

Answer 4

binocular
distance
double
blurred
photopic
spatial

Question 5

why assess vision?

Answer 5

. to allow us to quantify what people can and cannot see
. changes in vision health and disease
. occupational - visual requirements for some professions
. statutory - registration as severely sight impaired

Question 6

how did snellen innovate snellens chart

Answer 6

. snellen designed special characters - optotypes

Question 7

what are optotypes ?

Answer 7

letters , characters or symbols

Question 8

how is snellens chart arranged?

Answer 8

. arranged in a letter chart to test distance vision

. letters decrease in size as you go down

Question 9

what is snellens chart known as ?

Answer 9

. standard observer

. standard for comparison