When choosing glasses, one needs to consider factors such as the accuracy of the optometry, the material of the lenses, the fit of the men's sunglasses, and the usage scenarios. Scientific selection should aim to balance both vision correction and wearing comfort.
Professional optometry is preferred: It is necessary to undergo optometry at a reputable eye hospital or professional institution to avoid visual fatigue or worsening of myopia due to measurement errors.
Trial fitting verification: After the optometry, it is necessary to try on the sports glasses for 15-30 minutes. Through walking and reading tests, the comfort level should be confirmed. In particular, attention should be paid to whether the line-of-sight transition of the progressive multifocal lenses is natural.
Resin lenses: Lightweight and shock-resistant, suitable for daily use but require regular replacement.
PC lens: Highly impact-resistant. Recommended for use in sports scenarios.
High refractive index lenses (such as MR material): Suitable for people with high prescriptions, with thinner and lighter lenses.
Anti-blue light cycling eyewear: Suitable for people who use electronic devices for a long time.
Polarizing lens: Reduces glare interference during driving or outdoor activities.
The formula for calculating the deflection amount: (Mirror width + Middle beam width - Pupillary distance) / 2 ≤ 3. This ensures that the optical center aligns with the pupil.
For high prescriptions, it is recommended to choose good running sunglasses or running sunglasses to reduce the thickness of the lens edges.
Titanium alloy eyeglass frames: Lightweight and corrosion-resistant, suitable for sensitive skin.
Adjustable nose pads: Those with sunken noses should choose the high nose pad design to avoid pressure.
1. Common Parameters:
Refractive index
The refractive index of a material is the ratio of the speed of light's propagation in a vacuum to the speed of light's propagation in that material; or the ratio of the sine of the incident angle of light passing through the lens to the sine of the refracted angle. The refractive index is denoted by n. The refractive index of a lens is one of the important optical parameters that determine the lens's refractive power. The magnitude of the refractive index can be used to measure the thickness of the lens; the higher the refractive index, the thinner the lens can be made.
(Aberration number)
That is the dispersion coefficient. The reciprocal of dispersion, that is, the Abbe number is larger, the dispersion is smaller, and thus the clarity of the image is better. However, the higher the refractive index, the relatively smaller the Abbe number will be.
(3) Transmittance
Transmittance can be used to measure the clarity of a lens in viewing objects; that is, the higher the transmittance, the clearer the view.
(4) Density
The density of spectacle lenses is generally relatively high. As the refractive index increases, the density also increases, while the Abbe number decreases. Therefore, lenses with a high refractive index are thin; lenses with a large Abbe number have less chromatic dispersion at the edges; and lenses with a low density are lightweight, which are considered ideal spectacle lenses.
