Eye control starts in earnest from the time we are born. Some difficulties directing the eyes and generating complex binocular control may result in amblyopia, strabismus (turned eye), binocular dysfunction from vergence insufficiency and accommodation insufficiency.
Some problems resolve with sight correction in glasses and contact lenses. But some are variable problems recurring based on the amount of reading, or concentrated viewing with computer screens. These can occur within high precision sports such as target shooting and with fatigue in multisporting.
Attention, focus and directing the view are hard to sustain when the eyes are not correctly directed unconsciously to the desired location.
Binocular vision therapy works on these types of difficulties and generates a new understanding that we control the eyes globally before attending to the detail. This may be a short process to gain improvement for some but it will be a lifetime of visual awareness for others. It is not a surprise that eye control can be less accurate when we are tired and the view may blur or even double.
Eyes and Digital Screens
Children at school should be able to learn and adults to work safely with clear single sight.
Time: accrued time viewing and interacting with screens on a daily basis ( phone, computer, laptop, TV, xbox and tablet) at school & home throughout the week can generate visual fatigue. This includes scrolling through images and is not limited to reading print.
Features of screens:
Scroll: most scrolls move print upwards and this creates the effect of horizontal lines moving up. This causes an optokinetic effect where vision moves with the expectation that the eyes are moving outward to a distant object and diverge in the process. Once the scroll stops the eyes must converge to the print to focus the words. Repeating this to fill in documents or find specific paragraphs repeatedly through the day is an issue.
To help reduce fatiguing the fusion and focus reserves slow the scroll in the setup for touch screens; use a touch and finger slide to move the writing in sections; enlarge tool bars and print for less focus effort.
Development:Children's visual development is occurring throughout childhood and is not performing as adult vision systems do until growth has settled (for most boys over age 20 yrs and late teens for girls). It is known that the vision adapts to persistent viewing passed 20 minutes of reading. If this is draining on the vision then tiredness and fatigue would follow. This is a good time for a break of a similar time (likely to suit only younger children). The option to stand and shift to continue tasks within 1 hour of screen use helps keep vision available to use.
As the optometrist I enjoy working through these more difficult and thought provoking problems. My vision therapist and I guide people through individual programs to address these.
Visual fatigue and binocular dysfunction from screen and device use may resolve with glasses. However, resetting the binocular vision eye movements and focus may be necessary to fully reduce symptoms. It is also recommended to specifically improve habits or choices when viewing screens.
Our visual world is generated from a complex group of light, movement and expectation. When these do not align we experience discomfort and confusion. We look to resolve this.