Science

Visual environment

Spectacles
Contact Lenses
Orthokeratology
Pharmaceuticals
Visual Environment
Clinical Management
Myopia Progression
Mechanisms
Efficacy
Pathology

Visual environment

How do lighting levels and contrast affect vision with multifocal contact lenses?

In young adult myopes, Biofinity centre-distance +2.50 Add and NaturalVue multifocal contact lenses both showed reduced visual acuity in lower lighting and low contrast conditions, and especially with a glare source, compared to single vision. Reading rate under normal lighting was also reduced by 4-8%. The multifocal designs performed similarly, although Biofinity required more over-refraction for best distance acuity.

Examining the posture of myopic children during various near tasks

This study investigated the working distance and head posture of Chinese myopic children while reading, writing and playing video games. The average working distance across all tasks was 24.5cm, with the shortest working distance and largest head declination observed while children played video games. There was no influence of level of myopia or accommodative lag on working distance or head position. 

IMI Report on Risk Factors for Myopia

This report details non-modifiable and modifiable risk factors for myopia. Of the latter, Increasing the time children spend outside is an evidence-based intervention for myopia management. Near work is also a risk factor, although the causal relationship is less clear and future research with objective measures will provided more guidance on targeted clinical interventions.

New meta-analysis on digital device use and myopia

This new systematic review and meta-analysis has evaluated use of smartphones and tablets separately to computer use and other non-screen based near work. Results are still mixed but overall there was a trend for a slightly increased risk with mobile device use alone, which increased when combined with computer use. More objective measures of screen time are needed to further explore this link.

Lifestyle changes for Chinese school children during COVID-19 home confinement

A vision-screening program was able to provide data before and after Chinese schoolchildren were confined to home learning during the COVID-19 pandemic. Overall, more hours were spent indoors and less time was spent outdoors during this time, across all age groups. The younger schoolchildren had increased incidence of myopia and faster progression, whereas an increase in the prevalence of high myopia was found in the older children.

Increased myopia during the COVID-19 pandemic

Children aged 6 to 8 years old in China were found to experience a mean -0.30D myopic shift and a significant increase in myopia prevalence during a 5-month long COVID-19 home confinement period. Due to their age and corresponding critical stage in visual development, the change in the children’s environment and lifestyle may have been more responsible for their increased myopia than the increased online learning.

How accurate is subjective reporting of near work and outdoor time?

Young adults wearing the spectacle-mounted Clouclip device to measure viewing behaviour and light exposure also kept an activity diary. Mean daily near work and outdoor time were subjectively reported at about 150% of the objectively measured hours. This indicates the value of objective measures in research, as well as for clinical education and behaviour modification tools in future.

Outdoor time works to delay myopia onset – proof from Taiwan

A country-wide intervention to increase outdoor time in 5-6 year olds resulted in the prevalence of myopia decreasing from 15% in the 2014 cohort (before the intervention) to 8% in 2016 cohort (exposed to the intervention for up to two years) and was stable for three years thereafter. Increasing outdoor time works! 

How outdoor time influences myopia prevention and control

There is general widespread accepted belief that increasing time spent outdoors can be protective against progression of myopia. Xiong et al set out to better understand the research by performing a meta-analysis of 51 clinical trials and longitudinal studies that investigated the relationship between time spent outdoors and the risk of either developing myopia, progression of existing myopia or a myopic shift in refractive error.

Smartphone use in myopic vs non-myopic Irish students

This paper investigates the relationship between myopia, the objective measure of smartphone data usage and self reported duration of smartphone use in school children and university students with a secondary aim to assess whether study outcomes changed with age.