# Current Challenges Supporting School-Aged Children with Vision Problems: A Rapid Review
## 3 Overall Context of Vision Screening
### Instrumental Screening  
Instrumental screening methods are already appropriate for children 1 or 2 years old, and are recommended for children older than 2 years old under certain conditions [55]. Instrumental vision screening includes supported instruments from the available automatic vision screening devices that use state-of-the-art technologies, e.g., autorefraction, retinal birefringence, or a photo screener [56]. Automated vision screening devices are used primarily for diagnosing refractive errors, media opacities, and misalignments of eyes in children and adults [57] (see Figure 2b). Instrumental technologies show high accuracy in identifying vision problems in children. [PERSON] et al. [58] showed that photoscreener-based instrumental technology could detect refractive errors in children (particularly useful in younger children (ages 3-5), preverbal children (under age 3), and nonverbal children) that may be missed in traditional  
Figure 2: Different tools and computer software programs supporting different phases in a vision screening: (**a**) Snellen chart used for traditional vision screening (image downloaded from [[https://en.wikipedia.org/wiki/Snellen_chart#/media/File:Snellen_chart.svg](https://en.wikipedia.org/wiki/Snellen_chart#/media/File:Snellen_chart.svg)]([https://en.wikipedia.org/wiki/Snellen_chart#/media/File:Snellen_chart.svg](https://en.wikipedia.org/wiki/Snellen_chart#/media/File:Snellen_chart.svg)), accessed date 12 October 2021); (**b**) Welsch Allyn Spot Vision Screener is an instrumental device used for measuring refractive error (image downloaded from [[https://www.gocheckkids.com/welch-allyn-spot-vision-screener](https://www.gocheckkids.com/welch-allyn-spot-vision-screener)]([https://www.gocheckkids.com/welch-allyn-spot-vision-screener](https://www.gocheckkids.com/welch-allyn-spot-vision-screener)), accessed date 12 October 2021); (**c**) C&Look is an eye-tracking computer software for screening functional vision problems. screening methods. The speed of vision screening is almost three times faster than the traditional method. [PERSON] et al. (2019) compared the results obtained via photoscreening technology with traditional chart methodology to identify amblyopia and reflective errors in preschool children. The results showed 82.9% of the children passed instrumental eye exams, while this rate was 64% through LEA chart-based methodology ([PERSON], 2019). The LEA chart has the same function for preschool and kindergarten children as the Snellen chart (Figure 2a) but instead of letters, it uses symbols. The acquisition of useful visual field measurements in children, particularly younger children, is difficult and sometimes impossible. Children with moderate and severe visual impairment, glaucoma, damaged brain, or a central nervous system abnormality, such as perinatal stroke or optic pathway glioma, should undergo visual field testing. The biggest challenge in visual field testing is recognizing when a child may have a visual field defect, especially if it combines with ADHD. Vision specialists and researchers commonly use standard automated perimetry (SAP) in clinical settings for visual field testing ([PERSON], 2019). The accuracy of visual field testing can be influenced by several factors, including time to respond, attention, fatigue, and stimulus size and duration ([PERSON], 2019). [PERSON] et al. (2019) investigated the visual field testing strategy for healthy school-aged children with the Goldmann perimeter and Humphrey Field Analyzer. In order to avoid fixation loss, different rewards, verbal instruction, and gamified response buttons were given to children. The results showed that children faced difficulties with Goldmann kinetic perimetry tests. They concluded that the visual field of children could be examined using static perimetry at the age of six.