GB 11533-2011 PDF English
US$105.00 · In stock · Download in 9 secondsGB 11533-2011: Standard for logarithmic visual acuity charts Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedureStatus: Valid GB 11533: Evolution and historical versions
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivery | Name of Chinese Standard | Status |
| GB 11533-2011 | English | 105 |
Add to Cart
|
0-9 seconds. Auto-delivery
|
Standard for logarithmic visual acuity charts
| Valid |
| GB 11533-1989 | English | 399 |
Add to Cart
|
3 days
|
The standard logarithmic visual acuity charts
| Obsolete |
Excerpted PDFs (Download full copy in 9 seconds upon purchase)PDF Preview: GB 11533-2011
GB 11533-2011: Standard for logarithmic visual acuity charts---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GB11533-2011
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 13.100
C 56
Replacing GB 11533-1989
Standard for logarithmic visual acuity charts
Issued on. DECEMBER 30, 2011
Implemented on. MAY 01, 2012
Issued by. Ministry of Health of the P. R. China;
Standardization Administration of the P. R. China.
Table of Contents
Foreword... 3
1 Scope... 5
2 Terms and definitions... 5
3 Design criteria for visual acuity charts... 9
4 Printing specification for visual acuity charts... 10
5 Use methods of visual acuity charts... 12
6 Visual acuity statistics... 16
7 Others... 17
Appendix A (Informative) Standard for logarithmic distant visual acuity charts... 18
Appendix B (Informative) Standard for logarithmic near visual acuity charts... 19
Foreword
3.1, 3.2, 3.3, 3.4, 3.5, 4.1, 4.3.2, 4.3.4, 5.2, 5.3, 5.6.1 of this Standard are mandatory.
The rest are recommended.
This Standard replaces GB 11533-1989 "The standard logarithmic visual acuity charts".
Compared with GB 11533-1989, the main changes of this Standard are as follows.
- Revise the Scope (Clause 1 of the 1989 edition; Clause 1 of this edition).
- Add the term and definition "Logarithm record" (2.13 of this edition).
- Modify the provisions on the maximum optotype size, the minimum optotype size,
and the measurable range of near visual acuity charts (3.6.2 of the 1989 edition;
3.6.2 of this edition).
- Modify the provisions on the breadth of near visual acuity charts (4.2.2 of the 1989
edition; 4.2.2 of this edition).
- Modify the number of optotypes in the first line of distant visual acuity charts
(Table 2 of the 1989 edition; Table 2 of this edition).
- Modify the provisions on the number of lines of optotypes, the number of optotypes
per line, and the line spacing of near visual acuity charts (4.3.2 and Table 5 of the
1989 edition; 4.3.2 and Table 4 of this edition).
- Delete the table to express the number of optotypes and line spacing of near visual
acuity charts (Table 3 of the 1989 edition).
- Add requirements for the orientation of adjacent optotypes (4.3.4 of the 1989
edition; 4.3.4 of this edition).
- Modify the record values on both sides of distant and near visual acuity charts AND
other printing requirements (4.3.5, 4.3.6, 4.3.7 of the 1989 edition; 4.3.5 and 4.3.6
of this edition).
- Add another regulation on the use method of distant visual acuity charts (5.1.1 of
the 1989 edition; 5.1.1 of this edition).
- Modify the provisions on the lighting of visual acuity charts (5.3 of the 1989 edition;
5.3 of this edition).
- Delete a method for the determination of extraordinary visual acuity (5.4.2.2 of the
1989 edition).
- Modify the minimum value that can be measured by the near visual acuity chart
[5.4.3.3 of the 1989 edition; 5.4.3.b) of this edition)].
- Modify the table for variable distance correction of near visual acuity chart (Table
7 of the 1989 edition; Table 6 of this edition).
- Delete two methods of special cases for variable distance application (5.5.2.2 and
5.5.2.3 of the 1989 edition).
- Add the informative Appendix "Standard for logarithmic distant visual acuity
charts" (see Appendix A).
- Add the informative Appendix "Standard for logarithmic near visual acuity charts"
(see Appendix B).
Appendix A and Appendix B of this Standard are informative appendices.
This Standard was proposed by and shall be under the jurisdiction of Ministry of Health
P. R. China.
This Standard shall be interpreted by Ministry of Health P. R. China.
This Standard was drafted by Wenzhou Medical University.
Main drafters of this Standard. Wang Qinmei, Wang Chenxiao, Ye Tiantian.
The previous edition of the standard replaced by this Standard is as follows.
- GB 11533-1989.
Standard for logarithmic visual acuity charts
1 Scope
This Standard specifies the design criteria, printing specification, use methods, and
visual acuity statistical methods, etc. of visual acuity charts.
This Standard is applicable to general physical examinations for children, adolescents
and adults aged 3 years and above, distant and near optometry and visual impairment
screening for physical examinations such as enrollment and recruitment. It can also be
used for reference in ophthalmology and optometry clinical aspects.
2 Terms and definitions
The following terms and definitions apply to this Standard.
2.1
Optotype
Various characters, numbers, and graphics etc. used to measure visual acuity.
2.2
Visual angle
The angle between two points on the external object at the eye nodal point (N),
expressed as α, in minutes (′) (see Figure 1).
2.3
Nodal point, N
The optical center of the eye's refractive system, which is about 7 mm behind the
corneal vertex on the optical axis of the eye. When light passes through the nodal point,
the direction does not change (see Figure 1).
2.5
Examine distance, d′
Actual examine distance.
The distance from the visual acuity chart to the eye nodal point (N) of the examinee
during the examination. The design distance of all optotypes can be selected as the
examine distance in actual use.
2.11
Fraction record
Use the examine distance (numerator) and the design distance (denominator) at the
same time to express the visual acuity, namely d/D or d′/D. Its essence is to express
visual acuity by the reciprocal of visual angle.
2.12
Decimal record, V
Use the reciprocal of visual angle to express the visual acuity. The unit of visual angle
is (′) (minute). It is formulated as.
2.13
Logarithm record
Use the logarithm of visual angle to express the visual acuity, i.e. lgα.
3 Design criteria for visual acuity charts
3.1 Optotype shape
Use a square “ ”-shaped optotype with three strokes of equal length. Each stroke or
gap is one-fifth of the side length of the square (see Figure 2).
3.2 Standard of normal visual acuity
It is stipulated that the visual acuity that can distinguish 1′ visual angle is the normal
visual acuity standard, which is recorded as 5-mark, that is, 5.0.It is equivalent to 1.0
visual acuity in decimal record, 6/6 or 20/20 visual acuity in fraction record.
3.5 Record
Use the 5-mark record method. For each additional line of optotypes above 3.0, the
record is added by 0.1, which is arranged in an arithmetical progression. Each line of
optotypes can be accompanied by the corresponding decimal record value (approximate
value) at the same time.
3.6 Directly measurable range
4 Printing specification for visual acuity charts
4.1 Paper
4.2 Breadth
4.2.1 The distant visual acuity chart adopts the 5K (777 mm×217 mm) breadth of 787
mm×1092 mm paper. The allowable deviation is ±3 mm.
4.3 Format
4.3.1 The distant visual acuity chart is arranged with 14 lines of optotypes from top to
bottom according to the size. The line spacing is 24 mm. The number of optotypes in
each line is shown in Table 2.
4.3.4 The number of each orientation of the optotypes is equal. The order of appearance
shall be randomly distributed. The orientations of two adjacent optotypes shall be
different.
4.4 Printing requirements
The optotype is thick black. The ink color is uniform. No white spots are exposed. The
boundary is clear. The lines are straight. The allowable error of optotype size is ±5%.
There are no black spots on white background.
5 Use methods of visual acuity charts
5.1 Placement distance of visual acuity chart (examine distance)
5.2 Placement height of visual acuity chart
5.2.1 The 5.0-line optotype on the distant visual acuity chart is the same height as the
eye to be examined.
5.2.2 The near visual acuity chart is perpendicular to the line of sight of the eye to be
examined.
5.3 Lighting of visual acuity chart
Artificial lighting shall be used. If direct lighting is used, the illumination shall not be
less than 300 lx.
5.4 Determination of visual acuity
5.4.1 Determination of general visual acuity
According to the general use method of the visual acuity chart, measure the smallest
line of optotypes that can be recognized by the examined eye (the number of correctly-
recognized optotypes shall be more than half of the total number of optotypes in this
line). Record the visual acuity record value of the line of optotypes, which is the visual
acuity of the eye.
5.4.2 Determination of extraordinary visual acuity
When the distant visual acuity exceeds 5.3 (2.0), the following method can be used to
measure.
5.4.3 Determination of low visual acuity
When the visual acuity is less than 4.0 (0.1), the following method can be used to
measure.
5.5 Variable distance application of visual acuity chart
5.5.1 General principles of variable distance application
According to the site distance, the design distance (see Table 3 and Table 4) of any line
of optotypes on the distant and near visual acuity charts of this Standard can be selected
as the examine distance.
5.5.2 Special cases for variable distance application
5.6 Record
5.6.1 The visual acuity measured according to this Standard is recorded by a 5-mark
record method, such as 5.2 or 5.2 (1.5).
5.6.2 The conversion of 5-mark record to decimal record and various fraction records
is shown in Table 7.The conversion formula is formula (5) or formula (6).
6 Visual acuity statistics
6.1 The visual acuity in 5-mark record can be used for direct comparison of visual acuity
level and statistical processing such as visual acuity average, standard deviation,
standard error, and significance test. An example is as follows.
6.1.1 The visual acuity comparison can be directly expressed by the number of visual
acuity differences (number of lines of optotypes).
6.2 All decimal records, fraction records, and values such as visual angle, optotype size,
and design distance cannot be directly compared and counted by the method of 6.1;
7 Others
Other methods of using the visual acuity chart shall comply with the general regulations.
5-mark record
......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.
Tips & Frequently Asked QuestionsQuestion 1: How long will the true-PDF of English version of GB 11533-2011 be delivered?Answer: The full copy PDF of English version of GB 11533-2011 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice. Question 2: Can I share the purchased PDF of GB 11533-2011_English with my colleagues?Answer: Yes. The purchased PDF of GB 11533-2011_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet. Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB 11533-2011 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds. Question 5: Should I purchase the latest version GB 11533-2011?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB 11533-2011 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically. How to buy and download a true PDF of English version of GB 11533-2011?A step-by-step guide to download PDF of GB 11533-2011_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).
Step 2: Search keyword "GB 11533-2011".
Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart.
Step 4: Select payment option (Via payment agents Stripe or PayPal).
Step 5: Customize Tax Invoice -- Fill up your email etc.
Step 6: Click "Checkout".
Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively.
Step 8: Optional -- Go to download PDF.
Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice.
See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9
|