For anyone prone to work involving prolonged concentration on nearby objects, such as books or screens, looking into the distance can help combat visual fatigue. So what is visual fatigue and how can it be avoided?
The Eye Accommodation Process
The human eye has the ability to accommodate to see at different distances. This natural ‘fine tuning’ of images so they always take shape on the retina – a condition of being able to see an object clearly – is facilitated by a change in the curvature of the lens, caused by a contraction of the ciliary muscles. This is also accompanied by a shrinking of the pupil so as to increase our depth of field.
For a normal eye, when relaxed, light coming from objects far away focuses naturally on the retina. In other words, the eye is capable of seeing distant objects clearly without any effort. On the other hand, it has to go through a process of accommodation to be able to clearly see nearby objects, to read and to write. Strenuous accommodation of the eye causes symptoms of visual fatigue such as eye pain and even migraines1. Looking into the distance therefore means the eye no longer needs to accommodate and can relax the contracting pupil and ciliary muscles.
Diagram of the eye when relaxed (top) and during accommodation (bottom) (Source: guide-vue.fr)
The 20-20-20 Rule
When experiencing visual fatigue caused by prolonged exposure to screens, also known as computer vision syndrome, it is often recommended that you look at an object 20 feet away for 20 seconds every 20 minutes. This is the 20-20-20 rule, as popularized by Dr. Jeff Anshell1. While working at a screen, our eyes are effectively focused on an object that’s close, i.e. the screen, which leads to constant effort of accommodation and limited eye movement (for example, we blink two to three times less).
Taking regular breaks to look at something far away is recommended in order to combat visual fatigue (Source: optometrytimes.com)
The Importance of Views from our Buildings
We spend 90% of our time inside buildings. For many, our jobs require us to focus on precise tasks for hours, often at screens, further increasing eye fatigue. On a personal level, practicing the 20-20-20 rule can improve our visual health. We can set ourselves up for success by setting alerts or reminders to take breaks at predefined intervals and we can opt for work stations when possible that offer views.
For building owners and architects, developing workspaces that maximize unobstructed views can drastically improve the occupant experience. A smart window solution that minimizes the need for shading systems, like blinds and shades, can promote improved visual health for occupants, and in turn, boost well-being and productivity.