The 20/20/20 rule is an eye care guideline designed to reduce digital eye strain: every 20 minutes, look at something 20 feet away for at least 20 seconds. It’s one of the most commonly recommended habits for anyone who spends long hours in front of a computer, phone, or tablet. There’s also a separate 20/20/20 rule in military law that governs benefits for former spouses of service members. This article covers both.
The Eye Care 20/20/20 Rule
When you stare at a screen for extended periods, your blink rate drops and your eye muscles stay locked in a fixed focusing position. This leads to a cluster of symptoms collectively known as digital eye strain or computer vision syndrome: dry eyes, blurred vision, headaches, and neck or shoulder pain. The 20/20/20 rule breaks that cycle by giving your eyes regular moments of relief.
The mechanics are simple. Set a reminder for every 20 minutes of screen time. When it goes off, shift your gaze to an object at least 20 feet away (roughly the length of a car and a half, or across a large room). Hold that focus for a minimum of 20 seconds. This relaxes the ciliary muscle inside your eye, which contracts to focus on close objects and can fatigue after sustained near work.
Does the Rule Actually Work?
A clinical study published in the journal Contact Lens and Anterior Eye tested the rule with participants who received regular reminders over a two-week period. Dry eye symptoms and overall digital eye strain scores decreased significantly while participants followed the reminders. However, those improvements faded within a week after the reminders stopped, suggesting the rule works best as an ongoing habit rather than a short-term fix.
The same study found no measurable changes in tear film quality or most binocular vision parameters during the two-week trial, though accommodative facility (how quickly your eyes shift focus between near and far objects) did improve. In practical terms, the rule reliably reduces how bad your eyes feel, even if two weeks isn’t long enough to reverse underlying physical changes from prolonged screen use.
How to Build the Habit
The hardest part of the 20/20/20 rule isn’t the break itself. It’s remembering to take one. A few approaches that help:
- Use a timer or app. Your phone’s built-in timer works, but dedicated break-reminder apps can run quietly in the background and prompt you at regular intervals without requiring you to reset anything.
- Anchor it to something visible. If your desk faces a window, pick a specific object outside (a tree, a building, a parked car) as your 20-foot target. Having a go-to focal point removes the mental friction of figuring out where to look.
- Pair it with blinking. During your 20 seconds of distance gazing, deliberately blink several times. Screen use can cut your blink rate by as much as half, and conscious blinking helps re-wet your eyes.
Beyond the rule itself, a few ergonomic adjustments reduce baseline strain. Position your monitor slightly below eye level so you’re looking slightly downward, which exposes less of your eye’s surface to air and slows tear evaporation. Reduce screen glare by adjusting your room lighting or using an anti-glare screen filter. Increase text size on your device so your eyes don’t have to work as hard to read.
The Military 20/20/20 Rule
In an entirely different context, the 20/20/20 rule refers to a federal provision that allows an unremarried former spouse of a military service member to retain certain benefits after divorce. To qualify, three conditions must all be met:
- 20 years of marriage. The couple must have been married for at least 20 years at the time of divorce, dissolution, or annulment.
- 20 years of creditable service. The military member must have performed at least 20 years of service that counts toward retirement pay eligibility. The member does not need to have actually retired.
- 20 years of overlap. At least 20 of the member’s creditable service years must have occurred during the marriage.
When all three criteria are satisfied, the former spouse keeps access to military medical care (TRICARE), commissary and exchange shopping privileges, and Morale, Welfare, and Recreation (MWR) program benefits like on-base theaters and fitness centers. These benefits continue as long as the former spouse does not remarry.
The 20/20/15 Variation
A related but lesser-known rule, the 20/20/15, applies when the marriage overlapped with only 15 to 19 years of creditable service instead of the full 20. Former spouses who meet this threshold receive transitional medical coverage (typically one year of TRICARE eligibility after the divorce) but do not retain the full suite of commissary, exchange, and MWR privileges that come with the 20/20/20 rule.
Which Rule Applies to You
If you landed here searching for a way to reduce screen-related eye discomfort, the eye care version is straightforward to start. Set a recurring 20-minute timer during your next work session and try it for a week. The research shows symptom relief is real but only lasts as long as you keep doing it, so consistency matters more than perfection.
If you’re a former military spouse evaluating your post-divorce benefits, the key question is whether all three 20-year requirements overlap. Review your marriage date, the service member’s total creditable service time, and the years those two periods ran concurrently. Military OneSource and your installation’s legal assistance office can help verify eligibility.