Why Do We Use Light Transmission Meter to Measure the Lens Transmittance?

Linshang Technology has a LS108 light transmission meter which is specially used to measure the transmittance of spectacle lenses. So why do we need to measure the light transmittance of glasses lenses? Below we have a simple understanding of the relevant knowledge of spectacle lenses. For the measurement of the spectacle lenses light transmittance, we generally use light transmission meters to measure the transmittance of blue, purple and visible light.

1. The harm of blue light to the human eye

Blue light is light with a wavelength between 400nm and 480nm. What is really harmful to the human eye is blue light within 400-440nm. This kind of light will cause macular lesions in our eyes if it is illuminated for a long time. Blue light can even cause eye blindness. Therefore, there are many films or glasses on the market that are known as anti-blue light and can filter blue light. So whether it is really anti-blue light or not needs to be detected with an light transmission meter .

2. The harm of purple light to the human eye

Purple light is a mixture of blue light and red light. The damage of blue light to human eyes can be seen from the content above. The penetrating power of red light is particularly strong and it is particularly harmful to the human eye, so the damage of purple light to the human eye is self-evident. If the human eye is exposed to pure purple light for more than three minutes, it will cause harm to the human body. If it is directly irradiated for more than 15 minutes, it can cause corneal damage or even electrooptic ophthalmitis. Severe pain in the eyes, foreign body sensation, photophobia, eye spasms, etc. So a good pair of glasses with anti-blue light effect is essential. The Linshang light transmission meter can measure not only the blue light transmittance of glasses but also the purple light transmittance.

3. The effect of the lens visible light transmittance on the human eye

The light transmittance of spectacle lenses is the basic optical performance of glasses. It is also the most important test of light transmittance of lenses. Because if the light transmittance of the lens does not meet the standard, it will directly affect the user's visual experience. Therefore, it is essential to detect the visible light transmittance of spectacle lenses. The wavelength of visible light is generally between 380nm-760nm. The light source most sensitive to the human eye is a light source at 550nm. The Linshang light transmission meter is an instrument for measuring 550nm visible light transmittance.

The Linshang light transmission meter can be used to measure visible light at 550nm, purple light at 395nm and blue light at 430nm. It is widely used. It can be used to measure not only spectacle lenses but also various anti-blue light materials and organic materials. Linshang Technology can also customize the waveband according to the needs of users!