Vision Screening Apparatus Dynamic Optotype Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional visual acuity testing methods are time-consuming and inefficient, particularly when screening large groups, such as kindergarten students, as they require individuals to read multiple characters on a Snellen chart, which can test their patience and is not effective for identifying those with neurological issues or refractive errors.
Innovation Solution
A vision screening apparatus and method that determines a Snellen equivalent based on refractive error and distance, adjusting optotype size dynamically to display appropriate characters, allowing for quicker identification of visual acuity and potentially referring individuals with refractive errors to specialists without full visual acuity testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional Snellen chart reading method is used, then visual acuity can be determined, but testing time is excessive and efficiency is low
Solution Approach 1:
The system performs photorefraction screening before the visual acuity test to predict the subject's visual acuity in advance. This preliminary action allows the system to pre-determine which optotype line the subject is likely to read, thereby reducing the actual testing time when the subject is presented with the chart.
Solution Approach 2:
The system dynamically adjusts the optotype presentation based on real-time factors including the subject's distance from the chart, predicted visual acuity from photorefraction, and demographic information. This dynamic adaptation optimizes the testing process by focusing on relevant lines rather than requiring the subject to read all lines sequentially.
2Measurement precision
If all lines of characters are presented for reading, then comprehensive visual acuity assessment is achieved, but the process becomes time-consuming and tests patient patience
Solution Approach 1:
The system extracts and focuses only on the critical lines that are relevant to the subject's predicted visual acuity level. Instead of presenting all lines from the Snellen chart, the system identifies and presents only those lines that will provide meaningful assessment data, thereby reducing examination duration while maintaining assessment accuracy.
Solution Approach 2:
The system changes multiple parameters including optotype size, number of lines presented, and chart distance based on the subject's photorefraction results and demographic information. This parameter optimization ensures that the examination is tailored to each subject's specific visual capabilities, reducing unnecessary testing while maintaining precision.
3Reliability
If visual acuity testing is performed without preliminary refractive error assessment, then complete visual function evaluation is possible, but time is wasted on subjects with significant refractive errors who would fail regardless
Solution Approach 1:
The system performs photorefraction screening as a preliminary step before the visual acuity test. This preliminary assessment predicts the subject's visual acuity based on refractive error, allowing the system to identify subjects who are unlikely to pass the visual acuity test despite having good neurological visual function. This prevents wasting time on subjects who would fail due to correctable refractive errors.
Solution Approach 2:
The system dynamically determines whether to proceed with full visual acuity testing based on the photorefraction results. For subjects with significant refractive errors, the system may skip the time-consuming visual acuity test and directly refer them for refractive correction, thereby increasing screening throughput while maintaining test validity for subjects who need comprehensive evaluation.
Data Source
AI summary
A vision screening apparatus conducts a photorefraction ocular screening test to generate refractive error data. Based on the refractive error data, a Snellen equivalent is determined. An evaluated person distance from the vision screening apparatus is also determined and used to generate an adjusted optotype size. The vision screening apparatus displays the optotype, adjusted for the Snellen equivalent and the evaluated person distance.