HMC & SHMC

HMC,the full name is "Hard Multi Coating",It is a lens coating technology with high  hardness,It has the characteristics of wear resistance, slip resistance, waterproofing, and oil pollution prevention.And it has anti blue light function.In addition, the HMC  can enhance the clarity and comfort of the lens.‌‌

HMC uses multi coating technology,Reduce the reflection of light on the surface of the lens,Avoid glare that interferes with vision,Improve light transmittance,Make the line of sight clearer,Can resist wear and tear during daily use,Extend the lifespan of lenses.

For people who frequently engage in outdoor activities,HMC coating can effectively reduce the damage of ultraviolet rays,Protect eye health for long-time use,For people who need to work or drive in front of a computer for a long time,HMC coating can reduce reflection and glare, and alleviate visual fatigue.

SHMC, the full name is "Super Hydrophobic Multi Coating",it is a super waterproof membrane layer,Mainly used to enhance the waterproof performance and stain resistance of lenses.

Specifically, SHMC coating can make the surface of the lens superhydrophobic,Compared to HMC, SHMC has better waterproof performance.It can effectively prevent water droplets from staying on the surface of the lens,Reduce the impact of water stains on lens clarity and mist on vision.This coating is suitable for occasions that require ultra strong waterproof performance,Excellent performance in rainy or humid environments,Especially suitable for people who need frequent outdoor activities.

‌DIFFERENCE

The main differences between HMC and SHMC are waterproofing, anti fouling, wear resistance, and light transmission performance. ‌The SHMC performs better in terms of waterproofing and anti fouling. ‌The SHMC is smooth,Water droplets will slide down like water droplets on lotus leaves, leaving no trace at all,Impurities and stains are not easily attached,Suitable for outdoor activities and sports use.There is almost no need to worry about the lenses getting dirty when wearing them in daily life.In addition, SHMC have stronger wear resistance and shock resistance,Not easily scratched or bumped by hard objects, with higher light transmittance,Can effectively filter blue and ultraviolet light,Long term use of the eyes will not be too tiring.

In contrast, HMC's waterproof and anti fouling capabilities are slightly inferior,Easy to stain and water droplets,Need to wipe frequently,The light transmittance and anti blue light effect are poor.

SHMC has higher transmittance and clearer field of view. ‌After special processing, SHMC can effectively reduce reflection and refraction,Provide a brighter visual experience.

Although the light transmittance of HMC is also good,But reflection phenomena may occur at certain specific angles. ‌

When selecting lenses, a simple test can be conducted to determine whether they are SHMC,Use an oil-based pen to draw on the lens. If the handwriting is not easily traceable, it indicates that the coating is SHMC;On the contrary, if the handwriting is obvious, it indicates that it is not SHMC.

The main cause of lens slippage during lens fitting，Including factors such as lens surface treatment, processing equipment, and processing accessories.

1.The coating of HMC/SHMC lenses is very smooth, which increases waterproof performance but also makes the lenses prone to slipping during processing.

2.Edge grinding machine malfunction,Insufficient clamping force,Bearing wear,The grinding wheel is not regularly replaced,such as those problems can cause the lens to slip.

3.Improper selection and use of double-sided tape, anti slip adhesive, and suction cups，It can also cause the lens to slip.

4.Some materials, such as PC lenses, are prone to slipping during processing due to their unique characteristics.

Solution

Equipment maintenance and repair:

Regularly inspect and maintain the edging machine,Ensure that its clamping force is sufficient,The bearing is working normally,The grinding wheel is replaced regularly.

Choose appropriate processing accessories: Use high-quality double-sided tape, anti slip stickers, and suction cups to ensure that they can firmly adhere to the lens.

Adjust processing method: Choose an appropriate processing method to avoid issues such as template or lens misalignment.

Through the above methods,

It can effectively reduce the problem of slipping during the machining process of HMC and SHMC,Improve processing efficiency and finished product quality.