Every beam of light that lands somewhere you did not intend is money you paid for and
wasted. Light pollution is not only an astronomy concern — it is the reason
residents complain about glare through bedroom windows, why floodlights annoy neighbours, and
why some outdoor installations burn far more power than they need to. The good news: the fixes
are simple and usually save money.
The Four Types of Light Pollution
| Type | What It Means | Typical Complaint |
|---|---|---|
| Glare | Excessive brightness in the eye | “I can’t see past that light” |
| Light trespass | Light spilling onto others’ property | “It shines into my bedroom” |
| Skyglow | Light escaping upward, brightening the sky | “You can’t see stars anymore” |
| Clutter | Confusing groups of bright lights | Distracting for drivers |
Why It Costs You Money
Light aimed at the sky or a neighbour’s wall does no useful work — you are paying to
illuminate nothing. Poorly aimed outdoor lighting also tends to be over-specified to compensate
for bad distribution, compounding the waste. Fixing spill often lets you use lower wattage for
the same usable light on the ground.
The Five Principles of Responsible Outdoor Lighting
- Useful: light only where there is a clear purpose.
- Targeted: direct light down, onto the surface that needs it.
- Low level: use the lowest brightness that does the job safely.
- Controlled: use timers, sensors and dimming so light is on only when
needed. - Warmer colour: avoid unnecessarily cool, blue-rich light at night in
sensitive areas.
Practical Fixes That Work
Shielding and optics. Full-cutoff or well-shielded fixtures emit almost no
light above the horizontal. This single change eliminates most skyglow and much of the glare.
Aiming. Floodlights tilted too far up throw light into the sky and
neighbouring windows. Aim them down and use the right beam angle instead of over-tilting.
Colour temperature. For residential streets, campuses and hospitality,
warmer light (3000K) is far less intrusive than very cool light, while still safe and clear.
Controls. Dimming after midnight or using motion sensing in low-traffic
areas cuts both nuisance and energy. A
CCMS makes this easy across an entire network.
Where This Matters Most
- Residential townships and gated communities (windows face the road)
- Hotels, resorts and hospitality (ambience and guest comfort)
- Sports grounds inside residential areas (spill control is essential)
- Industrial sites near housing or wildlife areas
- Coastal, forest and observatory-adjacent sites
Specification Checklist
- Shielded / full-cutoff fixtures that put light downward
- Correct beam angle instead of over-tilting
- Appropriate CCT for the setting (3000K in sensitive areas)
- Dimming, timers or sensors for late-night reduction
- A lighting design showing light levels and spill at boundaries
Frequently Asked Questions
What is light pollution?
Unwanted or excessive artificial light — including glare, light trespass onto property, and
skyglow from light escaping upward.
How do I stop my lights annoying neighbours?
Use shielded fixtures, aim them downward, reduce brightness where possible, and dim or
switch off during late hours.
Does reducing light pollution reduce safety?
No. Well-aimed, glare-free light usually improves visibility, because glare itself makes it
harder to see.
Which colour temperature causes less light pollution?
Warmer light (around 3000K) is generally less intrusive at night than very cool, blue-rich
light.
Reway supplies shielded, glare-controlled
outdoor LED lighting and CCMS controls for responsible, efficient outdoor installations. Ask for a spill-controlled lighting design →
