Contact lenses: types, features, what you need to know before use

Contact lenses correct vision in various of its disorders, such as nearsightedness, farsightedness, astigmatism and others. They are convenient, do not interfere with activity, give brighter, clearer vision, which can not provide even very high quality glasses. Let's consider the types of contact lenses. What are their features? What do I need to know before using them?

Features of contact lenses

Types of lenses for correcting visual impairment:

• Soft contact lenses are the most common type of contact lenses. They are designed to correct nearsightedness and farsightedness. They are also prescribed for astigmatism and presbyopia.
• Rigid contact lenses are more difficult to care for and are difficult to wear. They are prescribed for people with complex visual impairments, with increased dryness of the eyes, when soft lenses are not suitable. Rigid products have a higher permeability to oxygen. They are also the only means of correcting keratoconus - thinning of the cornea and changes in its shape.
• Night contact lenses during the period of sleep changes the shape of the cornea, and in the morning a person sees better without any means of correction. However, their benefit and harm according to experts is a controversial issue. Night lenses are prescribed by a doctor after a thorough examination, if there are no contraindications.

Contact lenses differ in the duration of use. Products of prolonged use are designed for a week or a month of use. They are treated daily with a special solution for disinfection. One-day contact lenses are designed for one use. After use, they are discarded. This is the most hygienic product of this type.

Each pair of contact lenses is individually packaged. It is convenient to take them with you when traveling and when it is not possible to carry out proper hygiene to long-wearing lenses.

What you need to know before using contact lenses

Pay attention to such parameters of these means of vision correction:

• Moisture content largely determines the comfort of putting on and using contact lenses. The longer the period of their use, the more moisture in them.
• Dk/t is a ratio indicating moisture content, lens thickness and material. This ratio determines whether oxygen will flow well to the cornea of the eye. Day use lenses should have a Dk/t above 80 units. If it is less than 80, it is better not to wear such products for more than 6-8 hours.
• You should not choose contact lenses without consulting a doctor. He will determine the shape of the cornea, make a diagnosis and according to it prescribe the type of lenses.

Before wearing contact lenses, it is important to take into account that they require careful and thorough care. If such products will remain contaminated and accumulate deposits, it can harm the vision and cause inflammatory diseases of the eyes. It is better to use contact lenses designed for one day, 2 weeks or a month. Products with a longer shelf life accumulate deposits, which increases the risk of complications.