Internet Site Backdrop


 Will any pair of orange “blue-blocking” glasses preserve evening-time melatonin onset? MAYBE NOT!

Will any pair of orange “blue-blocking” glasses preserve morning-entrained melatonin onset for a person who works a night shift? PROBABLY NOT! 

The following is a discussion on both the usage of our ‘blue-blocking glasses’ for typical sleep time and the non-typical sleep time for the night shift worker.

The preservation of evening-time melatonin onset is the result of certain color-wavelengths of light NOT ENTERING THE EYE (during the evening) or entering the eye, but in low enough intensities.  A young healthier eye will require LOWER intensities of evening light to maintain evening-time melatonin onset, than an older eye. An older eye has more yellowing of the lens, which naturally blocks out more light.

Some orange glasses, that might adequately preserve evening-time melatonin onset in a 57 year old person watching a TV screen 12 feet away, may not adequately preserve evening-time melatonin onset in a 17 year old using a computer screen a mere 3 feet away from their eyes, or a cell phone 1 foot from their eyes.

Therefore, it is important that melatonin-onset eyewear radically blocks the color-wavelengths of light that can disrupt evening-time melatonin-onset.

FACT: ALL orange “blue-blocking” glasses allow ALL COLORS, including blue, to enter the eye, but orange glasses that are effective at preserving evening melatonin onset do so because they remove nearly/almost all of the light that are the color-wavelengths that need to be removed to preserve evening-time melatonin onset.

It is the blue and bluish-green color-wavelength components of white light that mainly prevents evening-time melatonin-onset from occurring. The glasses LightForFitness.biz sells are GUARANTEED to only pass blue light, worst case, to approximately 0.016%, thus blocking 99.984% of the blue light from passing through the lens.

Provided below is the graph, “Orange OD3+”, that contains this information. This lens effectively passes approximately 48% of the light from a white light source.

NOIR logo

    (ORANGE LENS NOIR 6032) OD3+ BLOCKS 99.984% of BLUE LIGHT, but PASSES Yellowish Green, Yellow, Orange and Red
Color Spectrum Showing Color-Wavelength Boundaries in Nanometers
Color Spectrum Showing Color-Wavelength Boundaries in Nano-meters (nm)



%T is percent light transmitted (passed through) of a specific wavelength-color designated by nano-meters (nm).  Thus it can be seen on this graph that the T% is 90% plus, for red, orange and yellow color-wavelengths of  light that pass through this lens.

NOTE: (A “T” of 1, is a %T of 100%, which is the same as saying that the lens is perfectly transparent for that specific color-wavelength).

Regarding the term WAVELENGTH found on the bottom scale of this graph: this phrase is used to describe the colors of light because physicists typically don’t use names, like red or green, but use a more exact method by saying, for example, “700 nm,” which is red.

Why? Because 750 nm red is a redder red than 700 nm, and 700 nm is a redder red than 630 nm red, for 630 nm red is a very orange-ish red. Any wavelength between 620-750 nm is called red, but each wavelength of red possesses a different redness of red. Using wavelength as the identifier is a way to discriminate between all the versions of any particular color; as 555 nm: is green, but a very yellowish green, and 505 nm is also green, but a very bluish green, etc.

As the graph above depicts, the lens we use is very transparent for red, orange and yellow light, but, within the near center of the green-wavelength region (495-570 nano-meters), the lens transitions from a light passer to a light blocker. To the left of this transition slope, the T-curve would make it appear that 0% of the blue light color-wavelengths (450-495 nm)  manage to pass through the lens, but this is not the case.

This is why this graph also contains an OD curve, which means Optical Density, which is a way to scale and describe absorbance. Mathematically, OD (optical density/absorbance) is the negative log of T (transmission). In other words, OD is a clever way to describe a very low value of T and graph it, as the T% graph makes it look like a value of zero in the blue region (450-495 nm) while this is not the case.

An OD of zero means that 100% of the light passes through.

An OD of 1 would mean 10% of the light passes through.

An OD of 2 would mean that 1% of the light passes through.

An OD of 3 would mean that 0.1% of the light passes through; OD 4/0.01% and OD 5/0.001%, so on and so forth.

In the blue region (450-495 nm) on the graph above, we see that the worst case of OD is about 3.8 near 480 nm. The negative log of 3.8 is 1.6/10,000th or a T of 0.00016 which is a T% (Transmission) of 0.016%. Or stated otherwise, this lens’ weakest block of all blue light is 99.984% at 480 nm blue light. It could be said then that this lens will block 99.984%, or more, of any given wavelength of blue light. Now that’s “blue-blocking”!

OUR TRANSMISSION CURVE is why you should choose our melatonin onset eyewear!

So, how do we stack up against the competition?

Consumer Reports recently tested 3 blue blocking pairs of eyewear and rated them. Of the three they tested, CR gave the best score to Uvex Skyper safety eyewear. According to Uvex themselves, the Uvex SCT orange lens blocks 98% of the blue portion of white light.  Comparatively, the Uvex SCT orange lens passes 2% of the blue light, while ours passes 0.016%.

The UVEX SCT Orange lens passes 125 times more blue light than does ours. Is this important?


Why? Because we don’t know who will be using our melatonin onset eyewear, a young person or an older person. Will they be 12 feet from a TV screen or 3 feet from a computer screen, or one foot from a cell phone? Maybe the person is wearing these glasses in the bright morning as they are attempting to entrain melatonin onset to occur during the day, because they work a night shift and need to sleep in the day. Furthermore, if they are using them in the evening, are their eyes highly dark-adapted, making them more sensitive? How well does the frame fit that person’s face and block the blue light from entering around the frame and getting into the eye?

With all that we don’t know (where is the exact tipping point for any given person in any given situation for the suppression of melatonin onset) and with a blue light passing factor of 125 to 1 (Uvex vs. ours), there could be persons who ‘went cheap’ and didn’t get results but could have if they had chosen the better eyewear. So, if you are young and/or plan on being in front of a computer screen at night, I especially recommend more blocking. IF YOU ARE ENTRAINING YOURSELF FOR DAY SLEEP BECAUSE YOU WORK NIGHTS, BUY THE GREATER BLOCKING, BECAUSE YOU WILL NEED ALL THE HELP YOU CAN GET!

For persons who want even more protection, we can ALSO fit your eyewear with an orange lens with a OD of 7+ which means less than 1 millionth of the blue light will pass through the lens! See the graph below. This lens effectively passes approximately 48% of the light from a white light source.

Orange Lens OD7+
Orange Lens OD7+ BLOCKS 99.999998% of BLUE LIGHT, but PASSES Yellowish Green, Yellow, Orange and Red light

Color Spectrum Showing Color-Wavelength Boundaries in Nanometers

(NOTE: Uvex does supply a T curve but not an OD curve because super-critical guaranteed blocking is not the purpose of their eyewear, as it was not intended to be used for highly dangerous light sources. SUPER-Critical guaranteed blocking IS THE PURPOSE OF OUR EYEWEAR, that is why it is supplied with an OD curve, as it was designed to be used around highly dangerous light sources. The other two ‘blue-blockers’ tested by Consumer Reports does not supply a T curve to the customer, nor an OD curve as their eyewear also do not guarantee critical blocking parameters, for that is not what those glasses are designed for.)

How did we determine the color-wavelength point at which the melatonin-onset eyewear lens transitions between passing and blocking?

Our Melatonin-Onset Eyewear is MORE conservative than the eyewear used successfully in an experiment to determine if such eyewear could preserve melatonin onset in adults who work during the night shift in a well-lit setting.

The subjects did not use computer monitors during this work-time experiment.

Amazingly, yes, it was possible to maintain evening-time melatonin onset and preserve the release of melatonin throughout the whole night while wearing blue-blocking glasses in a generally well-lit nighttime environment. This experiment does not answer the question what would have happened if the workers were viewing computer screens all night with the blue-blockers they were wearing.

To read about this experiment online, click here: online link: Blocking Low-Wavelength Light Prevents Nocturnal Melatonin suppression with No Adverse Effect on Performance during Simulated Shift Work

Or for a PDF version of this paper, click here: pdf version: Blocking Low-Wavelength Light Prevents Nocturnal Melatonin Suppression with No Adverse Effect on Performance during Simulated Shift Work

The graph below is the transmission curve for the lenses they used in this experiment.

Color Spectrum Showing Color-Wavelength Boundaries in Nanometers

Comparing our ORANGE OD3+ graph’s ‘nearing-zero-T-point’ at about 550 nm and the graph above at about 520 nm, ours is 30 nano-meters further removed to the right, away from the blue region, than what was used in this experiment. We remove/block the mid-green, bluish green and the blue, where they included/pass mid-green light in the transmission.

Our 30 nm extra-barrier of protection was chosen to protect evening-time melatonin onset in environments that are even more light-loaded than what was utilized in this experiment with no computer screen exposure. Furthermore, this experiment was conducted on adults not teenagers, teenagers with perfectly non-yellowed eyeball lenses.

Also, imagine a person who is using our eyewear to entrain their melatonin onset to occur at 6 AM, the time they leave their night shift job and then drive home in the bright summer morning sunlight, hoping to fall asleep at 9am. This person is facing a huge challenge. That morning outside light load is orders of magnitudes greater than what a computer screen or evening artificial light can generate. To buy glasses that can more than handle the light load found adequate for a given EVENING-TIME  experiment makes sense.


Because red, orange, yellow, green, blue and violet light ALL CAN CONTRIBUTE TO THE SUPPRESSION OF MELATONIN ONSET. Red is the least contributive, orange the second least, yellow the third least, green the fourth least, and blue the most contributive. With mid-green, you are getting pretty close to EVENING intensity values in normal settings that can begin to significantly lower your chances of preserving melatonin onset. Thus, we provide the mid-green barrier in the lens we sell. This extra barrier is intended to secure melatonin onset in the young, as they have clearer eyeball lenses than the adults used in the above experiment.

We have sold our lenses to persons with grade-school evening-computer-using children with good results, but for those still wanting an even greater ‘nano-meter’ barrier, we can fit our eyewear with a red lens.

See our red lens transmission curve below. This lens effectively passes approximately 9% of the light from a white light source. I would suggest this lens to a person especially struggling to re-entrain melatonin onset for the morning time, for sleeping during the day, due to night shift work. In very bright environments I would even suggest the possibly of using  our goggle versions to overcome any light from entering the eye from around the frame.

RED Lens OD5+
RED Lens OD5+ BLOCKS 99.993% of BLUE LIGHT, but PASSES Amber, Orange and Red light

Color Spectrum Showing Color-Wavelength Boundaries in Nanometers

Below is the link to our selection of melatonin onset eyewear. This purchasing site assumes the customer will want the ORANGE OD3.5+ lens, but, if a customer wants the ORANGE OD7+ or the RED OD5+, they will need to email or call me for this special order. The ORANGE OD7+ lenses will add $50.00 to the cost. The RED OD5+ will add $80.00 to the cost. Ordering these special lenses will also take longer for shipment. Soon these special lenses will be an easy selection option on the website.

A useful link for all persons interested in using melatonin-onset eyewear would be how to use – MELATONIN ONSET EYEWEAR – simple plan .

For persons facing the prospect of working night shift, I recommend reading – night shift plan


purchasing MELATONIN-ONSET EYEWEAR click on LightForFitness.biz

  • designed to stop (*) all colors of light “bluer” (blue = 400nm) than yellow-green (555 nm)
  • (*STOP: meaning that a specific color {wavelength measured in nm} is attenuated between OD=3.5+ thru 4+ meaning a reduction of light of a specific color {wavelength} from between about 1/5,600th down to less than 1/10,000ths)
  • designed to transmit (T)/pass (T greater than 90%) all colors of light “redder” (red = 800 nm) than yellow-green (555 nm)
  • a total light passage of 48%
  • effectively blocks the colors (wavelengths measured in nm) of light known to suppress melatonin onset prior to sleep in adults
  • to be worn prior to sleep
  • beginning to wear the eyewear 11.5 hours prior to awakening maximizes melatonin duration in the bloodstream
  • can be worn at the natural time of sunset, BUT this will cause some “summer adaption” to occur during the summer months, thereby reducing melatonin duration in the bloodstream
  • use while watching TV or any other indoor activity that involves evening artificial lighting
  • varieties include several styles and sizes: 14 FITOVERS, 8 Non-FITOVERS and 6 Prescription Insert-able.




Leave a Reply

Your email address will not be published. Required fields are marked *