The vision section (abbreviated “VIQ”) provides personal interview data on several vision topics.
Topics and the target population groups in the VIQ section:
All survey participants 12 years and older were eligible for the first set of questions on blindness and general conditions of eyesight. Participants 20 years and older were asked further detailed questions about activity limitations due to their vision and cataract operation. Participants 40 years and older were eligible for a new set of questions on eye diseases, including glaucoma and age-related macular degeneration.
These questions were asked before the physical examination, in the home, using the Computer-Assisted Personal Interviewing-CAPI (interviewer administered) system. Hand cards showing response categories were also used for some questions. When necessary, household interviewers read the hand cards to respondents.
Several types of quality control were implemented to ensure that high quality data were collected during the survey.
The CAPI system is programmed with built-in consistency checks to reduce data entry errors. CAPI also uses online help screens to assist interviewers in defining key terms used in the questionnaire.
Additional details describing the quality assurance/quality control processes are provided in the survey procedures manuals.
Frequency counts were checked, “skip” patterns were verified, and the reasonableness of responses to the questions was reviewed.
The 2007-2008 vision questionnaire data is the same as the 2005-2006 publicly released file.
In addition to the vision questionnaire data, general vision examination and special ophthalmic examination data can be found in the vision section and ophthalmology section of the NHANES 2007-2008 Exam Files (VIX and OPX). These data may be linked using the unique survey participant identifier, SEQN.
Although these data were collected as part of the household questionnaire, if they are merged with the MEC exam data, exam sample weights should be used for the analyses.
Please refer to the Analytic Guidelines for further details on the use of sample weights and other analytic issues. The Analytic Guidelines are available on the NHANES website.
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Yes | 7164 | 7164 | VIQ031 |
2 | No | 8 | 7172 | |
7 | Refused | 0 | 7172 | |
9 | Don't know | 1 | 7173 | |
. | Missing | 0 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Yes | 8 | 8 | VIQ071 |
2 | No | 0 | 8 | |
7 | Refused | 0 | 8 | |
9 | Don't know | 1 | 9 | |
. | Missing | 7164 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Excellent, | 2405 | 2405 | |
2 | Good, | 3287 | 5692 | |
3 | Fair, | 1133 | 6825 | |
4 | Poor, or | 271 | 7096 | |
5 | Very poor? | 64 | 7160 | |
7 | Refused | 0 | 7160 | |
9 | Don't know | 5 | 7165 | |
. | Missing | 8 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | None of the time, | 4235 | 4235 | |
1 | A little of the time, | 1312 | 5547 | |
2 | Some of the time, | 966 | 6513 | |
3 | Most of the time, or | 300 | 6813 | |
4 | All of the time? | 348 | 7161 | |
7 | Refused | 0 | 7161 | |
9 | Don't know | 4 | 7165 | |
. | Missing | 8 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | No difficulty | 4454 | 4454 | |
2 | A little difficulty | 842 | 5296 | |
3 | Moderate difficulty | 321 | 5617 | |
4 | Extreme difficulty | 138 | 5755 | |
5 | Unable to do because of eyesight | 74 | 5829 | |
6 | Does not do this for other reasons | 95 | 5924 | |
77 | Refused | 0 | 5924 | |
99 | Don't know | 3 | 5927 | |
. | Missing | 1246 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | No difficulty | 4757 | 4757 | |
2 | A little difficulty | 717 | 5474 | |
3 | Moderate difficulty | 236 | 5710 | |
4 | Extreme difficulty | 73 | 5783 | |
5 | Unable to do because of eyesight | 49 | 5832 | |
6 | Does not do this for other reasons | 94 | 5926 | |
77 | Refused | 0 | 5926 | |
99 | Don't know | 1 | 5927 | |
. | Missing | 1246 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | No difficulty | 4716 | 4716 | |
2 | A little difficulty | 663 | 5379 | |
3 | Moderate difficulty | 243 | 5622 | |
4 | Extreme difficulty | 116 | 5738 | |
5 | Unable to do because of eyesight | 39 | 5777 | |
6 | Does not do this for other reasons | 148 | 5925 | |
77 | Refused | 1 | 5926 | |
99 | Don't know | 1 | 5927 | |
. | Missing | 1246 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | No difficulty | 5236 | 5236 | |
2 | A little difficulty | 406 | 5642 | |
3 | Moderate difficulty | 168 | 5810 | |
4 | Extreme difficulty | 57 | 5867 | |
5 | Unable to do because of eyesight | 27 | 5894 | |
6 | Does not do this for other reasons | 29 | 5923 | |
77 | Refused | 0 | 5923 | |
99 | Don't know | 4 | 5927 | |
. | Missing | 1246 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | No difficulty | 5133 | 5133 | |
2 | A little difficulty | 501 | 5634 | |
3 | Moderate difficulty | 172 | 5806 | |
4 | Extreme difficulty | 61 | 5867 | |
5 | Unable to do because of eyesight | 22 | 5889 | |
6 | Does not do this for other reasons | 35 | 5924 | |
77 | Refused | 0 | 5924 | |
99 | Don't know | 3 | 5927 | |
. | Missing | 1246 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | No difficulty | 4871 | 4871 | |
2 | A little difficulty | 167 | 5038 | |
3 | Moderate difficulty | 43 | 5081 | |
4 | Extreme difficulty | 14 | 5095 | |
5 | Unable to do because of eyesight | 57 | 5152 | |
6 | Does not do this for other reasons | 349 | 5501 | |
7 | Never drove | 425 | 5926 | |
77 | Refused | 0 | 5926 | |
99 | Don't know | 1 | 5927 | |
. | Missing | 1246 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | None of the time, | 5132 | 5132 | |
1 | A little of the time, | 413 | 5545 | |
2 | Some of the time, | 228 | 5773 | |
3 | Most of the time, or | 68 | 5841 | |
4 | All of the time? | 82 | 5923 | |
7 | Refused | 0 | 5923 | |
9 | Don't know | 4 | 5927 | |
. | Missing | 1246 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Yes | 631 | 631 | |
2 | No | 5300 | 5931 | VIQ090 |
7 | Refused | 0 | 5931 | VIQ090 |
9 | Don't Know | 4 | 5935 | VIQ090 |
. | Missing | 1238 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Right eye | 89 | 89 | |
2 | Left eye | 98 | 187 | |
3 | Both | 443 | 630 | |
7 | Refused | 0 | 630 | |
9 | Don't know | 1 | 631 | |
. | Missing | 6542 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Yes | 263 | 263 | |
2 | No | 3747 | 4010 | VIQ310 |
7 | Refused | 0 | 4010 | VIQ310 |
9 | Don't know | 14 | 4024 | VIQ310 |
. | Missing | 3149 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Right eye | 35 | 35 | |
2 | Left eye | 49 | 84 | |
3 | Both | 162 | 246 | |
7 | Refused | 0 | 246 | |
9 | Don't know | 17 | 263 | |
. | Missing | 6910 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Yes | 148 | 148 | |
2 | No | 3844 | 3992 | End of Section |
7 | Refused | 0 | 3992 | End of Section |
9 | Don't know | 32 | 4024 | End of Section |
. | Missing | 3149 | 7173 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Right eye | 30 | 30 | |
2 | Left eye | 22 | 52 | |
3 | Both | 85 | 137 | |
7 | Refused | 0 | 137 | |
9 | Don't know | 11 | 148 | |
. | Missing | 7025 | 7173 |