Home Office Lighting: How to Set It Up and Reduce Eye Strain

Table of Contents

• The short version: three layers, and less light than you think
• Why does one overhead light make a home office hard to work in?
• How much light does a home office desk actually need, in lux?
• What colour temperature should home office lighting be?
• Where should your monitor sit relative to the window, and how do you kill glare?
• How bright should your screen be compared with the wall behind it?
• Does light flicker matter?
• What actually reduces digital eye strain?
• How do you light a basement or windowless room through a Canadian winter?
• What ValuHub's team learned putting this guide together
• Which ValuHub products fit these use cases?
• Sources
• FAQ

The short version: three layers, and less light than you think

Good home office lighting uses three layers: soft ambient light filling the room, a task lamp aimed at paper, and some light on the walls. Sit beside the window, never facing it or backing it. A screen makes its own light, so it needs less ambient light than reading print does.

That last point is the one most lighting articles get backwards. The Canadian Centre for Occupational Health and Safety (CCOHS) puts computer tasks at 75–300 lux and reading printed material at 200–500 lux. British Columbia's occupational health regulation is blunter: it files "VDT screens" in its lowest illumination category, minimum 50 lux, while prolonged or critical reading sits four categories up at 500 lux. Your monitor is a lamp. Stop lighting it.

Why does one overhead light make a home office hard to work in?

Because a single ceiling fixture has to do three jobs at once and can only do one. Natural Resources Canada's home lighting guide describes four layers — ambient, task, accent and decorative. CCOHS uses three categories: general lighting, localized-general lighting, and local or task lighting, the last of which "often allows the user to adjust and control lighting and provides flexibility for each user."

Ambient light is the soft, diffuse light filling the room. NRCan says it "reduces shadows and creates a sense of openness and comfort." Its job is not to light your work — it is to stop the rest of the room going dark around a bright screen, which is what makes your eyes ache after two hours.

Task light is the desk lamp, and it exists for paper. CCOHS is specific about aim: "Make sure that the task lamp illuminates the document and not the monitor."

Accent light sounds purely decorative, but in a work room it earns its place by putting light on vertical surfaces. NRCan's wall washing technique "puts light where we see it best — straight ahead on the walls" and is "a great method of creating soft ambient light."

Stripping ambient light and relying on a task lamp is a mistake, and there is Canadian evidence for that. In a National Research Council Canada study published in LEUKOS, 31 participants were given a task light and a dimmer for the ceiling lighting; turning the task light up barely changed the ambient level they chose. The authors concluded participants "preferred to maintain illumination on non-task surfaces, and to avoid extreme luminance ratios."

NRCan adds the control instruction that matters more than the fixtures: "Dimmers or switches should be used for each layer of light." Three layers on one switch is still one layer. If you are building the whole room, our ordered guide to a remote work setup covers chair, desk, monitor and network in sequence.

How much light does a home office desk actually need, in lux?

Between roughly 75 and 500 lux, and which end depends entirely on whether there is paper on the desk. Lux is lumens per square metre: how much light lands on a surface, not how much a bulb emits.

One note on sources. The document the industry cites is ANSI/IES RP-1, the Illuminating Engineering Society's office lighting standard, and it sits behind a paywall. We have not bought it, so we will not quote it. The table below uses CCOHS and British Columbia's occupational health regulation — both free to read, both built on the same task-category structure the IES framework established.

Why a screen needs less ambient light than paper

CCOHS states the mechanism in one line: "The monitor itself is a source of light. As such, it does not require additional illumination from other sources." Paper is not a source of light. It shows you anything only by reflecting light that arrived from somewhere else.

So the two most common mistakes look like opposites but are the same error. Flooding a screen-only desk with 700 lux washes out contrast and adds glare for no benefit. Working at 80 lux with printed pages makes you lean in to read, which is how a lighting problem becomes a neck problem — WorkSafeBC notes poor lighting "can also contribute to muscle soreness and fatigue by causing you to adopt awkward postures."

One honest wrinkle: OSHA's numbers run higher than the Canadian ones, because with LCD monitors "higher levels of light are usually needed for the same viewing tasks (up to 73 foot-candles)," against 20–50 for older CRT guidance. Modern screens resist washout better, so the ceiling has risen. The floor has not.

Age changes the answer

NRCan is direct: "We require as much as double the light by age 50 as we did at 20." It adds that older eyes are more susceptible to glare, "so we need the extra light to be diffused." More light and softer light, together — raising the bulb wattage gets you the first half and makes the second half worse. To check your own level, a phone light-meter app gives an order of magnitude, which is enough to tell 100 lux from 500. Measure flat on the desk, once at 10 a.m. and once after dark.

What colour temperature should home office lighting be?

Around 3500–4000 K for daytime work, warmer in the evening. Natural Resources Canada gives a specific home office recommendation: "Use a cooler lamp (3500 K is a good choice) than in the rest of the home."

Correlated colour temperature describes how warm or cool light looks, on the Kelvin scale. NRCan: "the higher the Kelvin number, the cooler the light source." ENERGY STAR puts it the same way — "Lower K means warmer, yellowish light, while higher K means cooler, bluer light." It says nothing about how hot the bulb runs, and the scale runs backwards from how people talk about colour, which is why 5000 K "daylight" bulbs get bought by accident.

Be careful about the evening half of that advice. Bright light plainly has physiological effects — that is the basis of light therapy for winter-pattern depression, described below — but it does not follow that a 4000 K desk lamp at 200 lux is a drug. Switching to warmer, dimmer light at night is a comfort recommendation with a plausible mechanism, not a clinical prescription, and we will not inflate it into one. The practical version is NRCan's rule: put the daytime task lamp and the evening ambient lamp on separate switches.

What is CRI, and why do cheap bulbs make a room look flat?

Colour rendering index is a 0–100 scale. NRCan defines it as a measure that "describes how well colours are rendered under a particular light source." Two bulbs at exactly the same 3500 K can render skin, wood and printed colour completely differently, because colour temperature describes the light's tint and CRI describes its completeness.

A low-CRI lamp is missing chunks of the spectrum. Objects cannot reflect wavelengths that never arrived, so reds go muddy, skin goes grey, and the room reads flat even when the lux meter says the level is fine. Buying a brighter bulb does not fix it.

Shop by this: ENERGY STAR certified bulbs must have a CRI of 80 or greater, per the U.S. Department of Energy, and NRCan's home lighting designs specify ">80 CRI" throughout. Eighty is the floor, not the target — for a room where you appear on video calls, 90 or above is a noticeable step up and costs very little now. One caveat: CRI averages a set of test colours, so two lamps rated 82 can handle deep reds quite differently. It is still the only number on the box.

Where should your monitor sit relative to the window, and how do you kill glare?

Perpendicular to the window — sitting beside it, with the window off to one side. Never facing it. Never with your back to it.

WorkSafeBC gives both reasons in one passage: "If you face a window, outside light shines directly into your eyes, making it difficult to focus on the screen. If you sit with your back to a window, you may have problems with reflections or high light levels." CCOHS states the rule generally — "Position the work station so that windows and fluorescent light tubes are parallel to the worker's line of sight" — and OSHA puts it as a right angle: "Place the face of the display screen at right angles to windows and light sources."

Direct glare versus reflected glare

Direct glare is bright light reaching your eye straight from the source. CCOHS attributes it to "very bright light from poorly positioned light fixtures" or "sunlight." This is the facing-a-window case: your pupils constrict to cope with the bright thing behind the screen, and the screen — unchanged — now looks dim and washed out. Turning the monitor brightness up chases the problem instead of solving it.

Reflected glare is light bouncing off a surface into your eye. CCOHS lists the sources as "light reflected from polished, shiny or glossy surfaces," "glass on picture frames or windows at night," and "monitors or screens." This is the backing-onto-a-window case. CCOHS puts it plainly: "The monitor also acts as a mirror."

British Columbia's regulation defines glare as "brightness within the field of vision that causes eye fatigue or loss in visual performance," and section 4.67 requires control of brightness ratios, reflectance values and glare. The definition is the useful part: glare is not about how much light there is, but where the bright thing sits relative to where you are looking.

The mirror test

WorkSafeBC's diagnostic takes thirty seconds and beats anything you can buy. "Sitting in your normal position, place a mirror — with the reflective side facing you — against your screen, then your document holder, and then on your work surface. In the mirror, you will be able to see possible sources of glare such as overhead lights and task lights." Your eye cannot tell you which fixtures are hitting the screen; the mirror can, because it obeys the same reflection geometry. Anything visible in it is a glare source; anything not visible is not, however bright. Two supporting fixes from the same guide: matte finishes, because "glare is made worse by light-coloured, shiny finishes on work surfaces or behind monitors, or by white paper scattered on top of a work surface"; and, as a last resort, a glass anti-glare filter rather than nylon mesh, which "can reduce the clarity of the letters on the screen."

Glare troubleshooting: symptom, cause, fix

How bright should your screen be compared with the wall behind it?

Close to equal. Not brighter by a factor of ten, which is what a bright screen against an unlit wall in a dark room gives you.

The numbers come from National Research Council Canada's office lighting work, which quotes the Illuminating Engineering Society's guidance: "the luminance ratio between a task and adjacent surrounds should not exceed 3:1, and across a person's field of view, the ratio of maximum to minimum should not exceed 10:1."

The more interesting figure is what people choose when nobody is telling them. In an earlier NRC study, participants given control over several lighting circuits settled on "an average desktop to background luminance ratio of 1.7:1, and an average computer screen to background luminance ratio of 0.8:1." Read that second number again. Left alone, people made the wall behind the screen slightly brighter than the screen. Nobody sets out to work in a dark room with a glowing rectangle in it; they end up there because they only have one switch.

The same paper shows what a badly balanced room measures: ambient lighting at 100–150 lux on the desktop plus a bright task light produced a 6:1 ratio between the lit desktop and the document holder, and roughly 15:1 across the wider field of view. The condition participants preferred had both layers at moderate output, 300–500 lux away from the lamp, and ratios nearer 2.5:1 and 6:1. Balance, not brightness.

Bias lighting, described honestly

Bias lighting means putting a modest light behind the monitor, aimed at the wall, so the surface the screen sits against is lit rather than black. It closes the screen-to-surround ratio, which is what the 3:1 guidance asks for. Be clear about its status: bias lighting is not named in CCOHS, WorkSafeBC, OSHA or the BC regulation. It is an application of a principle those documents do state, and cheap enough to test in an evening — warm-to-neutral bulb, aimed at the wall, kept dim. The zero-cost version is to turn the screen down. The American Academy of Ophthalmology advises matching screen brightness to the surrounding light level, and if your screen is the brightest object in the room you have already lost the ratio.

Does light flicker matter?

Yes, and it is the most under-diagnosed lighting problem in home offices, because the point of flicker is that you usually cannot see it.

CCOHS explains the mechanism: lamps running on AC power "produce light flickering at a frequency of 120 Hertz," twice the 60 Hz line frequency. People are "most sensitive to time-varying illumination in the 10–25 Hz range," and above roughly 50 Hz "most people can no longer distinguish between the individual flickers." So a 120 Hz flicker is invisible. That does not make it inert. CCOHS lists the possible effects as "blurred vision, eye strain, fatigue, headaches, nausea, or reduced visual performance for visual tasks," and notes epileptic seizures may also occur.

The issue has moved rather than gone away. Old fluorescent tubes flickered because of the ballast; LEDs can flicker because many dimming circuits switch them on and off rapidly rather than reducing output. A standard covers exactly this — IEEE 1789-2015, "IEEE Recommended Practices for Modulating Current in High-Brightness LEDs for Mitigating Health Risks to Viewers," setting out modulation frequency recommendations "to help protect against known potential adverse health effects." Almost no consumer bulb packaging cites it, which is the practical problem.

CCOHS's remedies are mundane and effective: "Replace bulbs on a scheduled basis. Old bulbs tend to flicker more and they are not as bright," check the fixture and ballast, raise it with the supplier. Its checklist reduces the whole thing to one line: "Lights provide steady illumination (e.g., lights do not flicker)." Two home tests: point a phone camera at the lamp, since rolling bands in the preview indicate modulation the rolling shutter is catching; and if one room reliably gives you a headache while lux level and glare both check out, swap the bulb first. Mismatched dimmer-and-bulb pairings are the most common household cause.

What actually reduces digital eye strain?

Breaks, blinking, correct screen distance, controlled glare, and treating dryness. Not, on current evidence, blue-light-blocking glasses.

It is common. A 2023 review in Clinical Optometry reports that "estimates of prevalence range from 33% of the general public, up to 50% for groups that are using digital screens for an extended period of time." The Canadian Association of Optometrists lists the symptoms as blurry vision, double vision, dry eyes, red eyes, irritated eyes, tired eyes, watery eyes and headache.

A large part of "eye strain" is dry eye

This is the part that reframes the problem. Staring at a screen suppresses blinking. The Canadian Association of Optometrists: "Staring leads us to reduce how often we blink to about only 4 times per minute from the average norm of 17 times per minute." The American Academy of Ophthalmology gives a less extreme figure in the same direction: "Humans normally blink about 15 times in one minute. However, studies show that we only blink about 5 to 7 times in a minute while using computers." The two measured differently and disagree on the rate; they agree on the direction and roughly the scale.

Blinking spreads tear film across the eye surface. Blink a third as often and the surface dries, producing grittiness, stinging, redness and the reflex watering people find so confusing. The AAO's remedies follow: blink deliberately, use artificial tears, run a humidifier in dry air. Canadian winter heating makes that last one relevant — our comparison of air purifiers and humidifiers for Canadian homes covers which symptoms point to which machine.

The 20-20-20 rule, and what it is worth

The Canadian Association of Optometrists states it as: "Every 20 minutes, take a 20-second break and focus your eyes on something at least 20 feet away." CCOHS gives the metric version — 20 minutes, 20 seconds, 6 metres. The AAO recommends the same.

Honestly framed: the rule is endorsed by every major eye-care body, costs nothing and carries no risk, but it is a rule of thumb rather than a validated dose. The numbers were chosen to be memorable, not because 20 minutes beat 18 or 25 in a trial. The principle underneath — sustained near focus fatigues the accommodative system, periodic distance viewing relieves it — is uncontroversial. Treat it as a prompt, not a threshold you have failed by missing.

On position, the Canadian Association of Optometrists asks for the screen "greater than arm's length (>50 cm) from your eyes and 20 degrees below eye level"; the AAO's version is about 25 inches (roughly 64 cm), angled so your eyes gaze slightly downward. Both also say keep the screen clean, since fingerprints and dust scatter light and cut contrast. Our guide to standard desk height and monitor position has the measurements.

Blue-light-blocking glasses: the evidence does not support them

Most content on this topic is selling something, so here is the plain version. A Cochrane systematic review published in 2023, led by Dr. Sumeer Singh, pooled 17 randomised controlled trials with 619 participants across six countries, with follow-up from less than one day to five weeks. Its conclusion on eye strain: "We found there may be no short-term advantages with using blue-light filtering spectacle lenses to reduce visual fatigue associated with computer use." Results on vision quality and sleep were unclear, and there was no evidence the lenses protect retinal health. The authors note their certainty is limited by the quality of the available evidence — this is "no clear benefit demonstrated," not "proven useless."

The American Academy of Ophthalmology is more direct: "There is no scientific evidence that blue light from digital devices causes damage to your eye," and "The Academy does not recommend any special blue light-blocking eyewear for computer use." Its explanation for the discomfort is the blinking one: "Most of us blink less when looking at screens, causing eye strain and dry eyes."

If you own a pair and like them, the Cochrane review found no consistent adverse effects, so there is no reason to bin them. Just do not buy them expecting the strain to go. None of this is medical advice, and no lamp is a treatment: persistent eye pain, vision changes or symptoms that do not settle with rest are reasons to see an optometrist, since uncorrected prescriptions are a recognised contributor and no amount of lighting fixes a lens problem.

How do you light a basement or windowless room through a Canadian winter?

Treat it as three problems: not enough daylight, no view, and a room where every surface eats light.

Light the vertical surfaces. The highest-value move in a basement. NRCan's wall washing puts light "straight ahead on the walls" and is "a great method of creating soft ambient light." A windowless room lit only by downlights reads as a cave whatever the lux level at desk height, because your sense of how bright a room is comes from the walls, not the floor.

Use indirect fixtures, not more downlights. NRCan's home office recommendation is that "direct/indirect suspended fixtures create a bright, but low-glare space for long hours of computer or paper work," and it warns that recessed lighting "should not be used to provide all the layers of light required in a design." CCOHS agrees: use "several small low-intensity light fixtures rather than one large high-intensity light fixture."

Keep the layers on separate switches so the room can be 3500 K at 2 p.m. and 2700 K at 8 p.m. With no daylight cue, that switch is the only thing marking afternoon from evening. And keep the task lamp — the basement is usually where the paper lives.

Short days, low mood, and what the evidence actually says

Canadian winter daylight is genuinely short, and how short depends on your latitude — National Research Council Canada publishes a sunrise/sunset calculator giving hours of illumination for any Canadian location and date, which beats guessing. On seasonal low mood, here is the evidence, stated carefully because this is health territory.

Seasonal affective disorder is real and reasonably common here: the Canadian Psychological Association reports that "approximately 15% of Canadians will report at least a mild case of SAD in their lifetime, while 2-3% will report serious cases."

Light therapy is an established treatment. NIMH describes it as a mainstay for winter-pattern SAD since the 1980s, delivered by "a very bright light box (10,000 lux) every day for about 30−45 minutes," usually first thing in the morning, from fall to spring. CAMH states that "many people who have SAD are helped by exposure to bright artificial light (light therapy)."

Light therapy as prevention is a different question, and the evidence is weak. A 2019 Cochrane review by Nussbaumer-Streit and colleagues found the evidence "is limited," that "methodological limitations and the small sample size of the only available study have precluded review author conclusions," and that the decision "should be based strongly on patient preferences." One small study is not a basis for anything.

And the part that matters here: a desk lamp is not a light therapy box, and this guide is not medical advice. The gap is a factor of twenty or more — a well-lit desk sits at 300–500 lux, a therapy box at 10,000. The CPA notes light therapy "is not suitable for everyone as there can be negative side-effects associated with this treatment including eye strain, agitation, headaches, and nausea," and that "light boxes should only be purchased after a discussion with your treating professional." NIMH adds that people with certain eye diseases, or on medications that increase light sensitivity, may need alternatives or medical supervision. If winter is affecting your mood, that is a conversation with a health professional, not a lighting purchase.

What ValuHub's team learned putting this guide together

Three things came out of checking the published guidance against what we actually stock and what customers ask.

First, we cannot sell the fix for most lighting complaints, and that changed how we wrote this. Our office range is desks, chairs and storage; there is no task lighting line. When we mapped the common problems — glare on the screen, a washed-out display, a room that feels dim at 4 p.m. — the best answers were rotating the desk ninety degrees, adjusting a blind, and putting light on a wall. All free or nearly free. There is no version of this article where the answer is a product we list.

Second, desk width and depth quietly decide your lighting options, and nobody asks about them. Our 55.1 in desk publishes its depth at 20.9 in (53 cm). That fits a screen at arm's length only if nothing else competes for the surface — and a task lamp base, placed correctly to the left of a right-handed worker, competes. The wider 58 in desk gives the lamp somewhere to go that is not in front of you, which matters because WorkSafeBC is explicit that a lamp directly in front "creates reflected glare from the desk or documents." We now read office desk listings for width and depth first.

Third, the question customers ask is rarely the problem they have. Office furniture enquiries are overwhelmingly about chairs and about whether a desk will fit a wall. Nobody has ever asked us about the wall behind their monitor. Yet the National Research Council figure — people freely choosing their own lighting settle near a 0.8:1 screen-to-background ratio — describes a room almost nobody has, because almost nobody has separate switches for separate layers. That gap is wider in lighting than in any category we write about, largely because most lighting advice online is written by people selling lamps. Good reason to read the CCOHS and WorkSafeBC pages yourself: free, Canadian, and not selling anything either.

Which ValuHub products fit these use cases?

Straight answer first: we do not stock a lighting range, so there is no lamp recommendation here. What our office products collection and household collection cover is the desk and storage side — the surfaces and layout that decide where light can go and where glare comes from. Each figure is a starting price; check the product page for current pricing.

• 58" Home Office Desk, Soft-Close Drawers — from $294.99 CAD. The width is the lighting argument: room for a task lamp to one side, per WorkSafeBC's guidance, without it crowding the keyboard or sitting in front of you. Not for a condo corner — measure the wall first.
• Desk with 8 Drawers, 55.1"W x 20.9"D x 29.5"H — from $264.99 CAD. Published dimensions make it easy to plan against a window wall: 53 cm deep, so settle monitor setback and lamp position before buying. Clearing paper into those drawers removes one of WorkSafeBC's named glare sources, "white paper scattered on top of a work surface." Not for anyone needing deep screen setback.
• Computer Desk with Keyboard Tray and CPU Stand — check the product page for current pricing. The tray frees the main surface, which is what a task lamp and a document have to share. Not for anyone wanting a minimal desk.
• Mesh Desk Chair, Adjustable Headrest — from $203.99 CAD. Relevant here only because seat height sets eye height, and eye height decides which fixtures reflect off your screen. Run the mirror test after adjusting the chair, not before. Not for anyone needing seat-depth adjustment.
• 4-Panel Folding Privacy Screen, 67" — from $130.99 CAD. A movable vertical surface: behind you it gives a clean video-call background; beside a west-facing window it blocks a low afternoon sun line. It is a sightline blocker, not a blind, and will not control daylight the way adjustable blinds do.
• 3-Panel Room Divider — from $119.99 CAD. The smaller version, for a basement or shared room that needs a defined work zone. Not a sound barrier and not a light source.

Before ordering anything as bulky as a desk, how ValuHub handles shipping and returns is worth five minutes.

Sources

1. "Lighting Ergonomics – General," Canadian Centre for Occupational Health and Safety (CCOHS). ccohs.ca
2. "Lighting Ergonomics – Survey and Solutions," CCOHS. ccohs.ca
3. "Lighting Ergonomics – Light Flicker," CCOHS. ccohs.ca
4. "Lighting Ergonomics – Checklist," CCOHS. ccohs.ca
5. "Office Ergonomics – Eye Discomfort in the Office," CCOHS. ccohs.ca
6. "How to Make Your Computer Workstation Fit You," WorkSafeBC (Workers' Compensation Board of British Columbia). Current edition: worksafebc.com. Text quoted here was read from the copy hosted by Health PEI, src.healthpei.ca (retrieved 26 September 2026).
7. Occupational Health and Safety Regulation, B.C. Reg. 296/97, Part 4 — General Conditions, sections 4.64–4.69 and Table 4-1 (Illumination levels). bclaws.gov.bc.ca
8. "Computer Workstations eTool – Workstation Environment," Occupational Safety and Health Administration (OSHA), U.S. Department of Labor. osha.gov
9. Newsham, G., Arsenault, C., Veitch, J., Tosco, A.M., Duval, C. "Task lighting effects on office worker satisfaction and performance, and energy efficiency." LEUKOS, vol. 1, no. 4 (April 2005), pp. 7–26. National Research Council Canada, Institute for Research in Construction (NRCC-48152). nrc-publications.canada.ca
10. "Home Lighting Design Guide Pocket Book," Energy Efficiency Reference Guide. Prepared by JEM Energy Inc. for CEATI International; hosted by Natural Resources Canada. natural-resources.canada.ca
11. "Purchasing Energy-Efficient Light Bulbs," Federal Energy Management Program, U.S. Department of Energy. energy.gov
12. "Light Bulb Purchasing Guide," ENERGY STAR, U.S. Environmental Protection Agency, March 2020. energystar.gov
13. IEEE 1789-2015, "IEEE Recommended Practices for Modulating Current in High-Brightness LEDs for Mitigating Health Risks to Viewers." Approved 26 March 2015. standards.ieee.org
14. "Computers, Digital Devices and Eye Strain," American Academy of Ophthalmology, 27 June 2024. aao.org
15. "Should You Be Worried About Blue Light?" American Academy of Ophthalmology, 10 March 2021. aao.org
16. "Computer Vision Syndrome (Digital Eye Strain)," Canadian Association of Optometrists. opto.ca
17. "20-20-20 Rule," Canadian Association of Optometrists. opto.ca
18. Singh, S., et al. "Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults." Cochrane Database of Systematic Reviews, 2023, CD013244.pub2. cochranelibrary.com. Plain-language summary: cochrane.org
19. Mylona, I., Glynatsis, M.N., Floros, G.D., Kandarakis, S. "Spotlight on Digital Eye Strain." Clinical Optometry, 2023, vol. 15, pp. 29–36. DOI 10.2147/OPTO.S389114. dovepress.com
20. Nussbaumer-Streit, B., et al. "Light therapy for preventing seasonal affective disorder." Cochrane Database of Systematic Reviews, 2019, CD011269.pub3. cochranelibrary.com
21. "Seasonal Affective Disorder," National Institute of Mental Health (NIMH), revised 2023. nimh.nih.gov
22. "'Psychology Works' Fact Sheet: Seasonal Affective Disorder (Depression with Seasonal Pattern)," Canadian Psychological Association. cpa.ca
23. "Seasonal Affective Disorder (SAD)," Centre for Addiction and Mental Health (CAMH). camh.ca
24. "Sunrise/sunset calculator," National Research Council Canada. nrc.canada.ca

FAQ

How many lux should a home office be?

It depends on the task. CCOHS puts computer tasks at 75–300 lux and reading printed material at 200–500 lux, and notes the familiar 300–500 lux office figure applies "where there is no task lamp in use." British Columbia's regulation sets a 50 lux minimum for VDT screen work and 500 lux for prolonged or critical reading. Screen-only desks want the low end; paper wants the high end.

What colour temperature is best for a home office?

Natural Resources Canada recommends 3500 K — "a cooler lamp than in the rest of the home." ENERGY STAR describes 3500–4100 K as "good for kitchens and work spaces," and the U.S. Department of Energy characterises 3500 K as "friendly, inviting" and 4100 K as "neat, clean, efficient." If you buy one bulb, buy 3500 K, and keep a warmer 2700–3000 K lamp on a separate switch for evenings.

Should my desk face a window?

No. Sit beside it. WorkSafeBC explains both failures: facing a window means "outside light shines directly into your eyes, making it difficult to focus on the screen," while sitting with your back to one causes "problems with reflections or high light levels." CCOHS asks that windows and light tubes run parallel to your line of sight, and OSHA says place the screen at right angles to windows.

Do blue light glasses help with computer eye strain?

Current evidence says no clear benefit. A 2023 Cochrane review of 17 randomised trials with 619 participants found "there may be no short-term advantages with using blue-light filtering spectacle lenses to reduce visual fatigue associated with computer use." The American Academy of Ophthalmology states it "does not recommend any special blue light-blocking eyewear for computer use," attributing the discomfort mainly to reduced blinking.

Why do my eyes feel dry rather than sore after a day at the screen?

Because you stopped blinking enough. The Canadian Association of Optometrists reports blink rate falling to about 4 times per minute at a screen, from a norm of about 17; the American Academy of Ophthalmology cites 5 to 7 against a norm of about 15. Blinking spreads the tear film, so less blinking means a drier eye surface. Deliberate blinking, breaks, artificial tears and less dry air all help.

Can a bright desk lamp help with winter low mood?

Do not treat a desk lamp as a light therapy device. Clinical light therapy uses roughly 10,000 lux for 30–45 minutes each morning, per NIMH — around twenty times a well-lit desk. The Canadian Psychological Association warns light therapy is not suitable for everyone and that light boxes should be bought only after discussing them with your treating professional. If winter is affecting your mood, that is a conversation with a health professional.