According to different standards, there are many types of contact lenses. According to the different materials of glasses, they can be divided into soft and hard:
Soft contact lenses are made of flexible plastic that allow oxygen to pass through the cornea. This type of contact lens will have a specific replacement cycle, such as daily throwing, monthly throwing, half-year throwing, and annual throwing.
Hard contact lenses, which are more durable, resistant to deposition, are easier to handle, and are less prone to tearing.
According to the wearing cycle, it can be divided into long-term and single-type:
Long-wearing type can be soft or hard. After each removal, you should rest at least one night without wearing contact lenses, otherwise it will cause eye damage.
Single-shot, a disposable contact lens, "one-time" refers to single use and disposal, as defined by the FDA. The “Daily Wear” (DW) contact lens was originally designed to be worn for a day and then removed before bedtime. Disposable contact lenses are useful for people who don't wear contact lenses often, or when it's possible or difficult to change contact lenses, such as on vacation.
Wearing contact lenses corrects vision and helps correct focus by correcting ametropia for a clearer vision.
Contact lenses allow the light to bend evenly in all directions (horizontal, vertical, etc.), which are commonly used to correct myopia and hyperopia.
The horizontal focus force of the vertical contact lens is different from the vertical focus force, so the astigmatism can be corrected. Some spherical rigid lenses can also correct astigmatism.
The beauty we often refer to is classified as a decorative contact lens in the United States and does not have corrective function. However, like other contact lenses, beauty may also cause complications, including eye irritation, redness, and infection.
Some of the beauty is just to color the iris, highlight the natural color of the iris, and some will completely cover the iris, greatly changing the color of the eye.
In recent years, in East Asia, including China, Japan, and South Korea, circular contact lenses are very popular. This kind of beauty makes a circle of dark areas around the iris, extending the appearance of the iris to the sclera, and wearing this contact lens. The iris looks bigger and wider, and the eyes look like dolls.
Meilu is not only a "vase" that can't be used in the middle, but also has more direct medical applications. For example, some contact lenses can restore the appearance of damaged or missing irises and restore the function of the iris to some extent.
About 5% of wearers are affected by contact lens complications each year, largely due to incorrect or no regular contact lens replacement.
One of the main causes of complications is that the contact lens itself constitutes an oxygen barrier that prevents the cornea from acquiring oxygen normally. The cornea requires a constant supply of oxygen to maintain complete transparency and normal function. When people are awake, the cornea usually gets oxygen in the air around it. When people are asleep, the cornea gets oxygen from the blood vessels in the back of the eyelids.
Long-term, chronic hypoxic conditions can cause corneal bacterial adhesion, microcapsules, corneal edema, endothelial cell hyperplasia, dry eye and myopia.
Long-term wear (more than 5 years) of contact lenses may reduce the entire corneal thickness and increase corneal curvature and surface irregularities.
In general, if you are using a multi-purpose contact lens solution, replace the contact lens storage case at least every 3 months or as directed by an ophthalmologist. If you use a contact lens solution containing hydrogen peroxide, be sure to use the new contact lens case that comes with each box and follow the instructions on the package or inside.
It’s not a good thing to wear contact lenses. The glasses are fragile and delicate. No matter which glasses you wear, you should pay attention to cleaning and how to use them. It is everyone’s responsibility to protect your eyes.