Light bulb shopping used to be relatively easy. Traditionally, we would replace our light bulbs based upon wattage. As governments began phasing out the use of incandescent bulbs, replacing them (with CFL, halogen or LED bulbs) has become trickier for consumers. Rather than relying on wattage — the amount of energy needed to power a light bulb — manufacturers are now labeling their products based on other outputs. The most important specs for understanding the effectiveness of light bulbs are lumens, lux, and color temperature.
When purchasing light bulbs, it is nice to know exactly how much light they will emit. This can be indicated in terms of lumen or lux — both of which are related to brightness, but they measure slightly different things.
Simply put, a lumen is the measure of brightness from a given light source (no matter what direction the light is). You’re probably familiar with the light output that a 60W incandescent bulb offers, for example. This wattage is not comparable to that of the LEDs that you’d find on the shelves today. In other words, we can no longer rely on solely comparing wattages to determine efficiency. Today, the higher the lumen measure, the brighter the bulb. Watts, on the other hand, measure energy used.
Lux also measures illuminance; however, it accounts for the total amount of light that falls on a given surface.
1 lux = 1 lumen × (square meters)
lx = lm × m2
A flux of 1000 lumens, for example, concentrated into an area of one square meter, lights up that square meter with an illuminance of 1,000 lux. At 10 square meters, the output is 100 lux.
Measuring lux is important because it reveals how many lumens you need to illuminate any given area. Keep this in mind if you need to illuminate larger areas in your home – the larger the area, the more lumens you need, which can generally be increased by adding additional lighting fixtures. Conversely, smaller spaces require fewer lumens for proper illumination.
Remember that your body is biologically programmed to receive different types of light exposure throughout the day (and night). The quality and quantity of your light exposure is essential for keeping your natural circadian rhythm (or sleep/wake cycle) on track. Below is a chart that outlines standard light exposure (in lux) while outdoors:
When choosing light bulbs for your home or office, be mindful of their light output (rather than just wattage). Ideally, you want to use bulbs that mimic natural sunlight during sunrise, midday, and after sunset. Proper lighting will help you maintain your energy and mood during the daytime, and promote deeper, better sleep at night.
Please note that color temperature is the third factor in the lighting trinity. For continued reading, be sure to check out Kelvin Color Temperature: What You Need to Know.
Junk light exposure when traveling can disrupt your circadian rhythm. Long-term exposure to light at night which accompanies shift work is listed as a probable carcinogen by the World Health Organization. Light at night has shown to be highly associated with significantly the risk of hormone specific such as cancers of the breast and prostate.
The flickering wavelength of light associated with LEDs and compact fluorescent lights emit blue light that inhibits melatonin production but also create a unique glare that impacts your retina causing eye strain, headaches, and physical and mental fatigue.
Red light and darkness move leptin and ghrelin into patterns that are (context dependent) associated with less hunger, while blue light does the opposite and can move both into patterns associated with more hunger.
Increase in cortisol, the stress hormone, due to circadian disruption. Memory recall is impaired with consistent sleep deprivation and may leave you distracted and not performing your absolute best.
The Importance of Melanopsin Cells
Your body requires some blue light at the right time of day and from the right sources. That’s why we created TrueDark® Sleep Technology that gives you 24-protection from junk light day and night.
Stop Junk Light with patented TrueDark® Twilights technology that frees your hormones and neurotransmitters to do their best work.
When the sun goes down, blue light isn’t the only junk light that can disrupt our sleep cycle and more than blue blockers are needed. Patented TrueDark® Twilights is the first and only solution that is designed to work with melanopsin, a protein in your eyes responsible for absorbing light and sending sleep/wake signals to your brain. Without melanopsin, melatonin can’t be accessed.
When you wear your Twilights for as little as 30 min before bed you prevent your melanopsin from detecting the wrong wavelengths of light at the wrong time of day. This supports your circadian rhythm and helps you fall asleep faster and get more restorative and restful sleep.
The highly advanced lenses in TrueDark® Daylights operate on a more advanced level than traditional blue blockers.
Blue light emitted from the sun helps regulate our sleep/wake cycle. However, in today’s world, we’re exposed to an overabundance of blue light, or junk light from artificial light. This includes hours spent in front of TVs, phones, and computers. It also includes time spent in artificial man made light with LEDs and fluorescent lights. Even if we’re simply reading a book, we’re doing that in artificial light which emit dramatically more blue light than the sun. That overexposure to junk light during the day has a dramatic impact on our neurotransmitters and hormones that are responsible for quality sleep.
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