Precautions for contact lenses
Contact lens, also known as corneal contact lens, corneal contact glasses, refers to a lens worn on the cornea of the eye to correct vision or protect the eyes, cosmetic contacts are contact lenses. According to the soft and hard material, it includes hard, semi-hard and soft three kinds. Contact lenses have greatly improved the appearance and convenience of patients with refractive errors such as myopia, farsightedness, and astigmatism. Moreover, it has a wide field of vision and vivid vision. In addition, it has also played a special role in controlling the development of myopia and astigmatism in teenagers and treating special eye diseases.
For the first time wearing contact lenses or colored contact lenses, friends will feel uncomfortable, one of the possible reasons is because of: corneal hypoxia. Under normal circumstances, our cornea needs to “breathe”, the oxygen permeability of contact lenses is an important indicator to evaluate the quality of contact lens materials. So the lens material has a high oxygen permeability is a very important factor in the selection of lenses.
Corneal long-term hypoxia is easy to lead to corneal related complications. Such as chronic corneal edema, corneal neovascularization, etc., contact lenses, especially color contact lense, meet the needs of the majority of people who love beauty. But be sure to fit their own contact lens products according to standard procedures, and strictly follow the care procedures for daily care. In particular, the oxygen permeability of lenses of different materials. Such as ordinary hydrogel lenses and silicon hydrogel lenses, is very different. And the time can be worn is also very different.
1.Can you sleep with contact lenses?
A: No. The normal cornea needs to “breathe”, the corneal oxygen supply mainly comes from the atmosphere when the eyes are open. And the corneal oxygen supply mainly comes from the horn and the eyelid conjunctival blood vessels when the eyes are close, which only accounts for 1/3 of the open eyes. So when wearing a mirror, it is easy to cause corneal hypoxia.
2.Why is the prescription of contact lenses different from that of frame glasses?
A: Frame glasses are place in front of the eye, while contact lenses are directly attach to the front of the cornea. There is no vertex distance effect of frame glasses, and according to a certain optical principle. The contact lens degree of myopia is slightly lower than the degree of frame glasses, far-sighted people are the opposite.
3.The thinner the contact lenses, the better
A: Not absolutely. Thin contact lenses increase oxygen permeability and improve comfort. But they are prone to lens dryness, dehydration, corneal dryness, corneal staining, and lens breakage.
4.Can you swim with contact lenses?
A: No. Unless you are wearing an eye mask, the microorganisms in the pool will cause lens contamination and the water will wash away the lenses.
5.Can contact lenses still be used after scars appear?
Small scars appear on the lens of different degrees of depth, severe will cause irritation to the eye symptoms, damage the corneal surface. It is necessary to ask the eye doctor to determine whether the lens should be replaced. Some small shallow scars on the surface of hard contact lenses can be trimmed by grinding. But soft contact lense cannot be trimmed.
1. Daily wear, the wearer wears the lens without sleep and with eyes open, usually for 12 hours a day.
2. Elastic wear refers to napping with lenses or occasionally sleeping overnight with lenses, not more than 2 nights a week (discontinuous).
3. Long wear, the wearer is still wearing the lens in the sleep state, and the lens is removed for several days.
4. Night wear contact lenses refers to wearing a lens when you sleep at night and taking it off when you get up in the morning. These night wear rigid contact lenses are also called orthokeratology lenses.
Experts pointed out that according to the way of wearing, it can be divide into long wear type and day wear type, night wear type. According to the length of the lens use cycle. It can be divide into abandoned type, regular replacement type, traditional type. The first wearer can increase the time according to 4h, 6h, 8h, and the time can be extend after slowly adapting.
How to choose the right contact lenses for you?
Wearing contact lenses if you often do not pay attention to some small details. It is easy to cause eye discomfort, and even affect the health of the eyes. Experts pointed out that contact lenses are a medical supply, should be check by a professional doctor and carefully evaluated before wearing, can not be casually purchase, otherwise improper use will cause a variety of related complications of the risk.
The visual correction effect of contact lenses on high myopia and high astigmatism is better than that of ordinary glasses. And the field of vision is not trouble by the frame limitation. But the wearing time should not be too long. Because if you wear contact lenses every day for a long time and are in an air conditioned environment for a long time. It is inevitable that the eyes are dry and tire, in addition to blinking more and resting more. Try not to wear contact lenses made of hydrogel for more than 12 hours continuously. Do not wear a mirror to nap, and do not wear a mirror to sleep at night. In addition, there are dry eyes, eyelashes inverted long, eyelid inversion or ectropion, living and working environment is high temperature and dusty myopia, it is recommend to wear contact lenses carefully.
In the choice of contact lenses, hard high-permeability lenses because more do not absorb the lipids in tears, proteins. And dust in the air. So it will not make the eyes allergic and inflammation. And hard lenses have a longer life, can be maintain for 3 to 5 years. But the disadvantage is that the wearer has a longer adaptation period, foreign body sensation. The lens is easy to slip, so it is not suitable for people engaged in sports. In addition, the emergence of disposable contact lense, because of the lower price and convenient health, especially suitable for allergic people to wear.
All in all
No matter what kind of contact lense you choose, you should first ask a professional doctor to examine the eye condition in detail, after assessing the health of the eye surface and tear function, after the lens is worn. It is necessary to evaluate the positioning, tightness and sliding degree of the lens under the slit lamp microscope. If the eyes feel red, swollen, painful, itchy, blurred vision. Or have foreign body sensation, seek medical attention as soon as possible to avoid delay.