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Is it possible to choose one on your own?
Choosing lenses for your eyes is not as easy as it seems. They may look the same, but there are dozens of features you need to consider before you buy them to prevent your vision from deteriorating.
Features such as:
- Optical power
- Lens material
- Texture (hardness)
- Wearing time
- Color
To determine the appropriate characteristics, you must first undergo an eye examination and consider parameters such as intraocular pressure, corneal curvature, eye muscle function, number of diopters, and peripheral vision.
It is impossible to obtain such data at home, so a visit to a specialist is necessary. Once you have a doctor’s prescription, you can safely go to the store and buy contact lenses.
Independent choice of lenses is dangerous, because you do not always know which diseases do not recommend wearing contact lenses. It is better to prefer glasses if you have them:
- Allergies;
- Glaucoma;
- Subluxation of the lens;
- Strabismus;
- Lachrymal disorder;
- Inflammation of the eye.
In many countries, the product can only be purchased with a prescription written by an ophthalmologist. This does not mean that you can experiment with your eyes. Only the consultation and assistance of an ophthalmologist will ensure quality results. It takes 20 minutes to diagnose your vision.
When choosing contact lenses, always pay attention to the information on the package. They will help you decide if the product is suitable for you or if you should consult a doctor first:
D – optical power index expressed in diopters.
BC – base curve index (from 8.4 to 8.6 mm). If this parameter is chosen correctly, wearing will not cause any discomfort.
DIA – diameter index (from 14 to 14.2 mm).
Dk/t – an indicator of the degree of oxygen permeability. It is assumed that the higher the better. The material should provide good air permeability.
There may even be a picture of the sun on the packaging. This is an indication that your eyes will be protected from the negative effects of UV radiation. The hourglass and numbers indicate when the model was developed. The time is reported from the moment you open the box, which compromises its integrity, not when you decide to put the product in.
Material to be created
Once you have determined the task of choosing lenses for your eyes on your own, it should be noted that they are created from only 2 main materials:
Hydrogel;
Silicone and Hydrogel.
The most important characteristic of each material is its ability to let oxygen pass through. A large part of the hydrogel is the fluid that allows air to enter the cornea.
The more water in the composition, the more oxygen is provided. This type of optical product is ideal for the visual organs, but the shelf life of such lenses is 1 day. Models based on hydrogels containing silicone can use silicone granules to deliver oxygen to the mucous membranes. This indicator depends on how well the eyes breathe. Another advantage of such products is their durability. They can be used from 1 week to 1 month. Acceptable wearing time is indicated on the package.
Some samples are designed not to be removed for 1 day, unlike some samples that need to be removed each time you go to bed.
Optical performance
If you’ve been living with a visual impairment for a long time, you’re probably already familiar with the process of choosing optics. During your exam, your eye doctor will tell you how many diopters you need to correct your vision.
The optical power of lenses and glasses is a different metric.
In the first case, the bond is made directly on the cornea, and in the second case, the bond is made at a distance from the cornea. These parameters differ in both sign and magnitude. At the time of diagnosis, your doctor will provide you with different diopter models and determine exactly which options will make your vision as clear as possible.
For example, instead of the usual 5 diopters, experts sometimes recommend models with a light power of 3.5.
How do I choose?
Choosing contact lenses also involves determining whether they are hard or soft. It is important to consider their differences. A hard lens can correct many eye imperfections, including scars and the effects of previous injuries, discoloration, and changes in color. Hard contact lenses not only provide an accurate and permanent optical system: They are durable. They are stable in place and do not move sideways with blinking. They are suitable for treating corneal and retinal diseases.
They are perceived as a foreign object at first, so you need to get used to wearing them. They are not recommended for people with retinal sensitivity. In general, these models should not be worn for more than 18 hours. After that, it is recommended to put them in a special solution. The selection process is very complicated, first you need to check your vision and seek advice from an ophthalmologist.
Soft-textured products contain a large amount of water, which makes them comfortable to wear, but reduces the allowable time of use. Colored models can change eye color and deepen shades.
Soft contact lenses have the following characteristics:
- They do not feel when worn and the patient quickly becomes accustomed to them. Because fingerprints can be left on the surface, they are easily damaged and require careful handling.
- The diameter of the product is selected to completely cover the cornea. Visibility is good from all sides.
- They are available in a wide variety (colors, conditions of use). They can leave a lot of protein deposits, they must be washed with a special solution. All models need to be cleaned and disinfected.
The procedure usually involves simply placing them in a container of solution and leaving them overnight. There is no clear answer to the question of whether hard or soft lenses are better. It depends on your personal preference. However, if your vision is deteriorating significantly, you may want to purchase a hard lens, which has great optical strength and holds its shape well. Soft, lightweight and comfortable to wear, they are suitable for those without severe vision problems or for beginners who want to get used to wearing them.
Length of use and wearing schedule
The rules for choosing contact lenses mean following the manufacturer’s and optician’s recommendations.
Today’s assortment is represented by products:
- Nocturnal;
- daily disposable;
- weekly
- bi-weekly;
- monthly.
The name itself tells you how long you can wear the chosen pair.
One-day lenses can be worn all day and even at night. However, after 1 day they are no longer suitable for further use. One-day lenses are usually sold in packs of 30, 90 or 180.
The one-week version can be worn for 7 days without removal. If you choose the two-week version, you will need to take them out several times to clean them from protein buildup. Monthly disposable contact lenses are designed to be worn for 30 days.
These models are usually removed only a few times for disinfection. Quarterly, six-monthly, and yearly disposable contact lenses are designed to be worn for 3, 6, and 12 months, respectively. Optical models require regular cleaning because protein plaque gradually accumulates on the surface.
The choice of product depends primarily on the purpose. If the samples are chosen to eliminate problems when working with paper in the office or at the computer, you can buy any variant. The main requirement is maximum oxygen permeability.
If you need vision correction, it is better to prefer products that can be worn for 2 weeks or more.
Appointment and features
It is recommended that you have your eyes examined once a year, even if you have no complaints. If you have worn contact lenses before, it is recommended that you have an eye exam every 6 months.
Incorrectly fitted lenses can cause discomfort during use, development of diseases and deterioration of vision. In case of wrong choice, the following symptoms appear after a few days:
- Blurred vision.
- Tingling and pain in the eyes
- Reddening of the mucous membranes.
- headaches
- Increased sensitivity to light.
All these symptoms indicate that the model is not suitable for you and needs to be replaced. To avoid further mistakes, it is recommended that you first consult an eye care professional. An experienced specialist will help you choose the option that will not cause an allergic reaction and will provide you with clear vision.
If these are your first lenses and you plan to use them for the first time, do not wear them for the entire 24 hours. This will allow your eyes to adjust. Start by wearing your chosen trial pair for 4 hours.
After 2 days, you can increase the time to 6 hours. If you do not feel any burning or pain, you have made the right choice.
First make a diagnosis, consult a specialist and determine the optical performance that suits you. It is necessary to have your cornea examined periodically as changes may occur and you may need to choose another pair.