Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Pre-Procedural Guidelines for Assessing Blood Pressure01:10

Pre-Procedural Guidelines for Assessing Blood Pressure

777
Accurate blood pressure assessment is crucial for diagnosing and managing various health conditions. To ensure the reliability of these measurements, healthcare professionals must adhere to standardized pre-procedural guidelines. These guidelines enhance patient safety and improve the overall quality of healthcare. The following steps are essential for obtaining accurate and consistent blood pressure readings, from using the appropriate tools to ensuring effective communication with the...
777
Errors in Taping01:18

Errors in Taping

274
Errors in taping arise from multiple factors that can significantly impact measurement accuracy in surveying. Misalignment of the tape, often due to human error, is one primary source. A skilled rear tapeman, using a telescope, can help correct alignment by guiding the head tapeman; however, human limitations still lead to small inaccuracies. These errors may include misplacement of pins or inaccurate tape readings due to common visual confusions, such as mistaking a six for a nine. Such...
274
Common Leveling Mistakes and Errors01:17

Common Leveling Mistakes and Errors

363
A survey team is tasked with determining the elevation difference between points Point A and Point B, separated by uneven terrain. They use a leveling instrument and a leveling rod.Common MistakesMisreading the Rod: During a backsight reading at Point A, the instrumentman observes the rod partially obscured by tall grass. Instead of reading 1.135 m, they mistakenly record 1.735 m due to the misalignment of the crosshair with the wrong graduation. This error adds 0.600 m to all subsequent...
363
Special considerations while measuring blood pressure01:28

Special considerations while measuring blood pressure

1.1K
When assessing blood pressure (BP), healthcare professionals must consider various factors and potential unexpected outcomes to ensure accurate readings and provide proper patient care. Adhering to these guidelines is essential to achieving the most reliable results.
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
1.1K
Uncertainty in Measurement: Reading Instruments02:46

Uncertainty in Measurement: Reading Instruments

49.7K
Counting is the type of measurement that is free from uncertainty, provided the number of objects being counted does not change during the process. Such measurements result in exact numbers. By counting the eggs in a carton, for instance, one can determine exactly how many eggs are there in the carton. Similarly, the numbers of defined quantities are also exact. For example, 1 foot is exactly 12 inches, 1 inch is exactly 2.54 centimeters, and 1 gram is exactly 0.001 kilograms. Quantities...
49.7K
Errors occurring during blood pressure monitoring01:25

Errors occurring during blood pressure monitoring

1.3K
Blood pressure monitoring is a crucial clinical procedure in diagnosing and managing various cardiovascular conditions. Despite its significance, the accuracy of blood pressure measurements can be compromised by multiple factors, potentially leading to either falsely high or low readings. These inaccuracies are critical as they can significantly impact patient care. So, it is vital to understand these challenges deeply and adopt strategic approaches to minimize errors.
Several factors...
1.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Visual field testing on the Envision head-mounted perimeter with and without gaming elements.

Ophthalmology. Glaucoma·2026
Same author

Optic nerve assessment with stereo photographs and ultra-widefield scanning laser ophthalmoscope images.

Clinical & experimental optometry·2024
Same author

Even-number measurement bias with Goldmann applanation tonometry in patients with glaucoma and glaucoma suspects.

Clinical & experimental optometry·2024
Same author

Time-of-Year Variation in Intraocular Pressure.

Journal of glaucoma·2021
Same author

Krukenberg's Spindles Strongly Suggest Long Anterior Zonule Associated Pigment Dispersion Mechanism in Older Patients.

Investigative ophthalmology & visual science·2020
Same author

Capsulorhexis challenge with long anterior lens zonules.

American journal of ophthalmology case reports·2020
Same journal

Tonographic outflow facility and intraocular pressure after standalone OMNI surgery.

Journal of glaucoma·2026
Same journal

Factors Associated With Retinal Nerve Fiber Layer Asymmetry in Primary Open-Angle Glaucoma Among Individuals of African Ancestry.

Journal of glaucoma·2026
Same journal

Haploinsufficiency of PITX2 in Four Chinese Families with Axenfeld-Rieger Syndrome.

Journal of glaucoma·2026
Same journal

Intraocular Pressure-Lowering Effect of Omidenepag Isopropyl as a Predictor for the Efficacy of Laser Trabeculoplasty.

Journal of glaucoma·2026
Same journal

Comparative Outcomes Between Micropulse and Slow-Coagulation Transscleral Cyclophotocoagulation in Eyes With Good Visual Acuity.

Journal of glaucoma·2026
Same journal

Machine Learning With Optical Coherence Tomography for Glaucoma Diagnosis.

Journal of glaucoma·2026
See all related articles

Related Experiment Video

Updated: Jan 3, 2026

Subjective Refraction Test Using a Smartphone for Vision Screening
05:36

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

1.6K

Even-number Measurement Bias With Goldmann Applanation Tonometry.

Anne Rozwat1, Daniel K Roberts1,2,3

  • 1Department of Clinical Education, Illinois Eye Institute, Illinois College of Optometry.

Journal of Glaucoma
|November 26, 2019
PubMed
Summary
This summary is machine-generated.

Examiners show a tendency to record Goldmann applanation tonometry (GAT) intraocular pressure (IOP) readings as even numbers. This even-number preference in IOP measurements varies with the IOP level, being less apparent in the 21-24 mmHg range.

More Related Videos

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter
05:14

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter

Published on: September 16, 2025

512
Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
07:11

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Published on: May 25, 2020

6.8K

Related Experiment Videos

Last Updated: Jan 3, 2026

Subjective Refraction Test Using a Smartphone for Vision Screening
05:36

Subjective Refraction Test Using a Smartphone for Vision Screening

Published on: October 18, 2024

1.6K
Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter
05:14

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter

Published on: September 16, 2025

512
Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential
07:11

Assessing Early Stage Open-Angle Glaucoma in Patients by Isolated-Check Visual Evoked Potential

Published on: May 25, 2020

6.8K

Area of Science:

  • Ophthalmology
  • Biostatistics
  • Clinical Measurement

Background:

  • Goldmann applanation tonometry (GAT) is a standard method for measuring intraocular pressure (IOP).
  • Previous observations suggested a potential bias in GAT readings favoring even numbers.
  • Limited research has explored the extent and variability of this phenomenon.

Purpose of the Study:

  • To investigate the distribution of GAT-measured IOP values in a large dataset.
  • To determine if a preference for even-numbered IOP readings exists.
  • To analyze how this potential bias varies across different IOP levels.

Main Methods:

  • Analysis of a large dataset comprising 69,537 right eye GAT IOP measurements.
  • Statistical examination of the distribution of recorded IOP values.
  • Assessment of the even-number preference in relation to specific IOP ranges.

Main Results:

  • A significant tendency for even-numbered IOP values was observed.
  • This even-number preference was minimal between 21-24 mmHg.
  • The bias towards even numbers increased as IOP readings moved further from the 21-24 mmHg range.

Conclusions:

  • Data suggest an examiner proclivity to record GAT readings as even numbers.
  • This examiner bias in IOP measurement is not uniform and varies with the IOP level.
  • Further investigation into measurement and recording practices in tonometry is warranted.