BS 4274-1:1968

Superseded

View Superseded by

Visual acuity test types Specification for test charts for clinically determining distance visual acuity

Available format(s)

Hardcopy , PDF

Superseded date

01-13-2003

Language(s)

English

Published date

01-26-1968

Publisher

British Standards Institution

Specification
1 Scope
2 Definitions
3 Range of letter sizes
4 Indication of letter size
5 Style and selection of letters
6 Spacing of lines
7 Spacing of letters
8 Proportions and line widths of letters
9 Dimensions of Landolt ring characters
10 Dimensions of illiterate E characters
11 Manufacturing tolerances
12 Luminance contrast
13 Lighting requirements
Appendices
A General recommendations on lighting for test charts
B Simple methods of lighting for externally
     illuminated charts
Tables
1 Range of letter sizes and numbers of letters per
     line
2 Minimum and maximum lengths of each line of letters
3 Summary of recommendations on lighting for test
     charts
Figures
1-4 Simple methods of lighting for externally
     illuminated charts. Methods 1-4

Basic requirements for test charts designed for either internal or external illumination, employing English (Roman) capital letters to determine the distance visual acuity. Provision is also made for the single letter C (Landolt or broken ring) and the single letter E (illiterate E) in various orientations.

Committee	CH/172
DevelopmentNote	Supersedes and renumbers BS 4274(1968) (10/1996)
DocumentType	Standard
Pages	12
PublisherName	British Standards Institution
Status	Superseded
SupersededBy	BS 4274-1:2003
Supersedes	BS 4274(1968) : AMD 9200