What is the purpose of the 20-20-20 rule?

Long periods doing any activity puts a strain on your muscles and causes them to fatigue. Injuries from over straining muscles can be common in the work or home where adequate health and safety practices are not encouraged. In the same way that the muscles of your body fatigue, the muscles in your eyes also fatigue from over working. Infact the effect of over working your eyes has a double effect of tiring the eye muscles and also causing tear-film disruption. Find out what you can do to keep your eyes healthy as a computer user.

The muscles in your eyes are responsible for intermediate and near focussing, that is computer distance focussing and reading a book focussing. The ciliary muscles in your eyes have to change the shape of your natural lens and hold it in that position for the entire duration of your computer or near activities. When doing this for long periods the ciliary muscle will become strained, resulting in an eye ache and/or mild headache (asthenopia). Allowing the muscle to relax is then the only way to relieve these symptoms.

What is the normal blink rate in a minute?

The normal blink rate varies depending on the situation. A resting blink rate is estimated to be between eight and 21 blinks per minute[1]. However, during conversation, the blink rate is believed to increase and average around 10.5 to 32.5 blinks per minute[1]. Another estimate suggests an average of 19 to 26 blinks per minute during conversation[1]. When focusing on a specific visual task, the blink rate is likely to drop[1].

Please note that these are average ranges and individual blink rates can vary.

The normal blink rate per minute for a healthy person should be about 15-20 blinks per minute.

What does a low blink rate mean?

A low blink rate can indicate various things depending on the context. In general, when someone is calm, focused, relaxed, or unaffected, their blink rate tends to decrease[1]. For example, during intense concentration or when engrossed in a captivating film, the blink rate may be low as the individual is absorbed in taking in as much detail as possible[1].

However, a consistently low blink rate can sometimes be associated with certain eye conditions. Dry eye syndrome is one condition where individuals may have a lower blink rate[4][5]. Insufficient blinking can result in poor tear distribution and potential damage to the ocular surface[3].

It’s important to note that a single low blink rate reading is not necessarily indicative of a problem. If there are concerns about the blink rate or eye health, it is advised to consult with a healthcare professional or an ophthalmologist for a proper evaluation.

Why is blink rate important?

Blink rate is important for several reasons. First, blinking helps to keep the eyes lubricated[1]. Each time we blink, tears spread across the surface of the eye, providing moisture and nutrients to keep the eyes comfortable and healthy[1].

Additionally, blinking plays a crucial role in maintaining clear vision. When we blink, the eyelids help to distribute tears evenly across the cornea, which is the clear front surface of the eye[1]. This ensures that the cornea remains smooth and transparent, allowing light to pass through and focus properly onto the retina at the back of the eye[1].

Furthermore, blinking is important for preventing eye strain and fatigue, particularly during prolonged visual tasks such as reading or using digital devices. Regular blinking helps to refresh the eyes, reducing dryness and preventing symptoms of eyestrain like redness, itchiness, or a gritty sensation[1][5]. Studies have shown that people tend to blink less frequently during these tasks, which can lead to increased discomfort and visual fatigue[2][3]. By consciously maintaining a natural blink rate, individuals can help alleviate these symptoms and promote greater visual comfort[5].

In summary, the blink rate is important because it helps to moisturize the eyes, distribute tears evenly, and prevent eye strain and fatigue. It is beneficial to be aware of and maintain a healthy blink rate, especially during activities that require prolonged visual focus.

Apps available to help with better blinking

There are apps available for you to download and use to remind you to take regular breaks. Lets be honest, we are not going to remember to take regular breaks without a prompt. This is where these apps can play an important role in reminding you.

Microsoft apps for computer eye strain



Android apps for computer eye strain


Eyecare 20 20 20

Blue light filtering for screen work

Blue light has been highlighted for some years now as being detrimental to our health. What we know of blue light is that it disrupts sleeping patterns if being exposed to it before bed. It is still not clear what blue light exposure causes over the longer terms in our eyes or on a day to day basis when using screen for prolonged period of time.

If you are concerned about the effects of blue light on your well being, you may want to invest in blue filtering glasses when using screens or blue filters in your prescription eyewear when you next go and have your glasses updated. What they will do is reduce some of the eye strain caused by blue light from screens, they also reduce scatter from headlights at night and they might help with your sleep if you use screens before bed.

Bear in mind your smart phone may have blue light adjustment anyway as many of the latest generation of smart phone screen have a settting to auto adjust the screen colour balance in the evenings. Even if they do have this adjustment, most will not have an app built in to remind your to take breaks and blink.

Eye drops for computer users

Eye drops for computer users are beneficial for supporting the tear-film. They provide symptomatic relief from he symptoms of dry eye. They come in the form of drops and sprays. The drops come in different viscosities, the more viscous having a temporary blurring affect of vision, which may not be practical during a work day.

Depending on how symptomatic you are, you may need to use all methods to keep your eyes from becoming strained. Start getting in to good habits and if you find you are still having problems, get in touch for an in depth assessment.

Tsubota, K., Hata, S., Okusawa, Y., Egami, F., Ohtsuki, T., and Nakamori, K. (1996). Quantitative videographic analysis of blinking in normal subjects and patients with dry eye. Arch. Ophthalmol. 114, 715–720. doi: 10.1001/archopht.1996.01100130707012

Karson CN, Berman KF, Donnelly EF, Mendelson WB, Kleinman JE, Wyatt RJ. Speaking, thinking, and blinking. Psychiatry Res 1981;5:3:243-246.

  1. “It’s Time to Think About the Blink – Review of Ophthalmology”
  2. Blink Rate Notice The Unnoticed A Secret Power – Body Language Matters
  3. Low Blink Rate Tied to Dry Eye Parameters – Review of Optometry
  4. Blink Rate Decreases During an Eye Exam – Review of Optometry
  5. Changes in blink rate and ocular symptoms during different reading – NIH PMC
  6. It’s Time to Think About the Blink – Review of Ophthalmology
  7. The benefits of blinking | AOA – American Optometric Association
  8. Blink Rate Patterns Provide a Reliable Measure of Individual … – Nature
  9. Importance of Blink Rate – PMC – National Center for Biotechnology …