The closer a person holds a book, phone, or laptop, the harder their eyes have to work to keep that item comfortably clear. As an object is brought closer to the face, accommodation, or focusing, has to increase to keep the image clear (like changing focus on your phone’s camera). In children, the amplitude (amount of focusing power), sustainability (ability to stay focused on something for a period of time comfortably), and facility (ability to quickly change focus between different distances) should be high. With overuse and with age, the lens has a reduction of both the focusing power and flexibility. Sustaining close viewing distances becomes uncomfortable, which is why many individuals need to wear reading glasses when they get older or have an accommodative dysfunction.
Also, when looking at an object far away, the eyes are parallel to each other. When an object comes closer, the eyes have to converge (cross in) to keep that image single. If the eyes have a problem turning in as a team (eye teaming) and do not both point at an object at the same time, the object will appear double and you will see two of something when it should be one.
Millions of Americans suffer from computer vision syndrome or digital eye strain and it has been magnified with recent events. Symptoms of computer vision syndrome are directly related to spending prolonged hours looking at screens of all kinds and include eye irritation, redness, dry eye, blurry vision, double vision, back pain, neck stiffness, eyestrain, and headaches.
With many children attending school through their devices and parents working on their computers from home, visual hygiene is more important than ever. If your eye doctor has prescribed reading glasses, make sure you use them while doing near work, as this could help with both your eye teaming and your eye focusing. If you or your child have not seen an eye doctor in the past year, make sure you make an appointment right away to get evaluated, especially if you are having any visual discomfort.
Here is a list of things parents and children can do to decrease eye strain and discomfort while spending the day at school or at working from home:
Keep your distance
Reading material should be no closer than the distance between the center of your middle knuckle to your elbow. This distance is even further when working on something larger such as a computer screen. The closer something is held, the harder your focusing system and your eye teaming system have to work, which can lead to eyestrain, headache, blurry vision, discomfort, double vision, and inability to optimally concentrate on and understand your work.
Be aware of your surroundings
Many people zone in on the computer screen or tablet and become too concentrated on what is going on directly in front of them (tunnel vision), which can contribute to visual discomfort after some time. To help improve peripheral awareness, you can place stickers on the top, bottom, right, and left of your screen and try to be aware of them at all times while doing your work. If the screen is so large that you can not see the sides when looking straight ahead, that probably means the screen is too big and you will have to move your head side to side to read or look at things from one side of the screen to the other – which can cause discomfort.
Make sure that both feet are touching the floor, your back is touching and supported by a back rest, the top of your screen is slightly below eye level, and the table and chair height is adjusted so your legs are bent in a 90 degree angle with your forearms parallel to the floor. If a child’s feet do not touch the floor, a small pad or step stool can be placed to allow them to rest their legs instead of having them dangel. If the chair is too deep to offer back support, a pillow can be placed between the child’s back and backrest so the child is able to rest their back on the pillow for support. Also make sure that the shoulders are relaxed and not rolled up toward the head.
Give your eyes a break
Your eyes need a break from focusing, teaming, and taking in information. A general rule to follow is the 20-20-20 rule. Take a 20 second visual break by looking at least 20 feet away, every 20 minutes. There are a great variety of 20 minute timers on the internet or a simple timer on your phone can be set. If you are not on a device, placing a bookmark one chapter (or several pages) ahead can help be a reminder for you to take a break. For some people, being distracted every 20 minutes is just simply…too distracting! So, setting a 30 minute timer is another option. The key is to look at something far away to give your focusing and eye teaming a break. Try to incorporate movement into this break to give by body a rest as well as your eyes. Simple, quick stretching exercises for your neck, back, arms, and legs can be a great addition. Keep in mind, going from looking at a computer screen to a phone (or visa versa) is not a visual break.
Keep hydrated and Blink
When people concentrate on something visual, they blink less. Blinking is how we keep our eyes moisturised and not blinking enough leads to a dry and irritated feeling and red appearance to the eyes. Staying hydrated by keeping a closed water bottle next to your work station and making a conscious effort to blink are key. To kill two birds with one stone, you can make one of the peripheral awareness stickers on your screen a written reminder to hydrate and blink. Some people may experience more dryness and irritation on the computer with their contact lenses, they should speak with their eye doctor about contacts that provide more moisture to the eye or consider toggling between glasses and contacts.
The room should be neither too dark nor too bright. Natural and even lighting is best. When reading or working on paper, the illumination on the reading material should be about 3x that of the surrounding background and should not produce any glare. This can be achieved by using a gooseneck lamp with an incandescent bulb such as a 60 watt bulb. Using two lamps on either side of the reading material can help eliminate shadows.
Tilted work surface
For computer screens, the very top of the screen should be slightly below eye level and tilted slightly away from you. For writing and text reading, a 20-25 degree sloping surface (such as a slant desk) should be used. This reduces tension and stress on the eyes, head, shoulders, and back. Remember that the writing / text material should be at least the distance from your knuckle to your elbow away, and further for computer screens.
Ultraviolet (UV) and short wavelength light from the sun is at a significantly much higher concentration than anything you can get from a computer screen. Blue light does interact with, and suppress, melatonin which in turn can interfere with our circadian sleep cycles. There is no clear cut evidence showing blue blocking lenses have any benefit but there anecdotal accounts of patients using blue blocking lenses and feeling less stress and strain on the eyes, especially when on their electronics. Before investing in a pair, you might want to try not stimulating your brain with light 1-2 hours before sleep and also decreasing the amount of blue on your screen (which in effect will do the same as the glasses). This can be done by putting your electronics into ‘night mode’ or decreasing the amount of blue your screen emits. If you’re not sure how to do that, just google it, or download one of a vast variety of free apps available for smartphones, tablets, and computers to do just that. It’s important to note that ‘computer glasses’ are not the same as ‘blue blocking glasses’, an eye doctor may prescribe ‘computer glasses’ specifically for a closer viewing distance to help prevent eye focusing and teaming problems.
Increasing the magnification on the screen so that text is 110-120% larger can help reduce squinting. Keep the working environment as clean and clear of visual clutter as possible. If you do have children at home, make sure that you are modeling proper visual hygiene behavior for them as they will take their cues from watching you.