Contact Lenses

Contact lenses are suitable for correction of various degrees of myopia, farsightedness and astigmatism. They can begin to be used from the child’s age, when he or she is able to put on and remove the contact lenses, and learn how to clean the lenses and strictly follow their wearing regimen. The exception is neonatal contact lenses, which are used in special cases and only under the supervision of a pediatric ophthalmologist.

The contact lenses vary in sizes and base curve radius, so the most appropriate contact lenses are chosen individually for each patient by first questioning the patient about his or her daily habits, when and how often the patient would be willing to wear, and for what purpose they are needed (sports, daily life and the like).

When choosing contact lenses, it is important to evaluate the condition of the front parts of the eye and corneal parameters. The required power of lenses is determined, corneal curvature, size of pupil and cornea are estimated, and corneal topography is performed. In choosing the type and material of contact lenses, it is also important to evaluate the quality of tear film.  But, when the contact lens is put on, its centering, movement and, of course, patient’s feelings are further evaluated.

…whether contact lenses may not be taken out for several days. Such a question often occurs when the patient has difficulty to learn how to put on and remove contact lenses. Optometrists and ophthalmologists most often do not approve sleeping with contact lenses, and even with extended wear contact lenses they recommend to enjoy quiet of the night only in certain cases where, for example, clear water is not available nearby, or the patient has gone to hike, or to some cultural event, taking  along the moisturizing eye drops.

To ensure that the wearing of contact lenses does not cause inconvenience to the patients, the trying-on of the contact lenses, as well as training in proper inserting, removal an, storage and hygiene of contact lenses is offered to the patients in the “Latvian American Eye Center”. For the convenience of the patients, the opportunity to acquire standard contact lenses and their care products is provided on site at the clinic. The selection of specific contact lenses – both soft and hard-, as well individual ordering are also provided.

However, it should be born in mind that trying-out of contact lenses takes longer time, compared with glasses, and requires regular visits to ophthalmologist or optometrist to evaluate eye health. It should also be taken into consideration that the contact lens care takes more time.  If you want to have a successful contact lens use experience, it is essential for them to ensure proper care and storage, as well as the lens wearing regimen shall be followed and regular eye health checks shall be carried out.

Knowing what contact lenses are right for you means understanding the differences between existing contact lens types.

Soft contact lenses are most popular and widely used type of contact lenses due to the comfort of their use and short adaption time that lasts for about one to a maximum of two days. Often the patient feels them comfortable after just 15 minutes to half an hour of use. They are ideal for occasional use.

Soft contact lenses gently cover entire cornea and steadily adhere to the eye throughout the day (less often fall out of the eye due to their good contact with eye surface). As a result, such lenses reduce the risk of foreign matters (dust, dirty, etc.) getting under the lens. Soft lenses are one of the best solutions for people who are engaged in contact sports.

However, it should be born in mind that when using soft lenses, they should not be allowed to dry out; otherwise the contact lenses can cause discomfort and impair visual quality, besides drier lenses are more exposed to damage. Also, soft lenses are more susceptible to protein and lipid deposits, they absorb environmental chemicals; this increases the likelihood of inflammation and infection.

By manufacturing material, the soft lenses are divided into hydrogel and silicone hydrogel lenses.

Hydrogel lenses are the contact lenses of older generation that were introduced in the early 1970s.They do not provide as much oxygen supply to cornea as silicone hydrogel contact lenses, but does not mean that the hydrogel lenses should be forgotten. Such lenses are ideal for short-time use, such as sports activities a couple hours a day, or for permanent wearing throughout a day. A minority of patients still experience a higher comfort wearing hydrogel contact lenses.

Silicone hydrogel lenses became available in 1999 and are more suited for continuous use, even during sleeping. There are contact lenses that can be worn for up to 30 days, provided that they are properly maintained and the correct usage regimen is followed. Silicone hydrogel contact lenses are easy to use and also affordable for most patients. Silicone hydrogel lenses should not be used in patients who are allergic to silicone.

By the way of usage the soft lenses are divided into dailies, two week/bi-week, or monthly contact lenses.

Dailies or disposable contact lenses, as the name implies, are designed for the use for one day (inserting once a day) and then they are disposed. This means that there is no need to use contact lens care products, clean them after use, and there is no need to purchase a lens storage container. When using disposable lenses, there is a lower risk of eye inflammation compared to reusable lenses; besides, thanks to the fact that they do not require care, the soft contact lenses also significant time savings that is especially important in today’s busy life;

Bi-week and monthly contact lenses require proper care and their usage regimen should be followed. Some contact lenses from different manufacturers are designed to be used even for several days, including the bedtime. However, such lenses are recommended only in exceptional cases that are to be evaluated by the ophthalmologist or optometrist in interaction with a patient. It is not recommended to wear two week and monthly contact lenses for more than 16 hours a day.

For great part of people, the hard lenses are associated with the ancient times when they were made of hard and heavy glass, causing great discomfort to their users. With the development of modern technologies, in the manufacturing of hard lenses, glass has been replaced by various lightweight air and gas permeable materials, so one no longer have to be afraid of hard lenses.  In addition, there are cases when hard contact lenses provide significantly better quality of vision than soft lenses. Hard contact lenses are often used for correction of high-grade refraction defects, such as corneal astigmatism, high degree of ametropia and in the case of keratoconus, also used in presbyopia patients being able to provide wider range of vision correction and greater visual acuity. Hard lenses are one of the best solutions for people whose profession involves fine work, such as jewelers, watchmakers, pilots, doctors- surgeons, etc.

Although the latest generation material of hard lenses provides much greater comfort, it should be taken into account that adaptation to them may take longer time compared with soft lenses.

One type of hard contact lenses is orthokeratological or overnight lenses, which are used only at night. Overnight lenses actively exert natural pressure on the cornea while the person is sleeping, slightly altering the curvature of anterior surface and smoothing the upper epithelial layers, resulting in an even load distribution and successful correction of low to moderate myopia. During the day, the lenses are removed and clear vision is provided throughout the day, even without them, giving a greater freedom in daily routine.

Another type of hard contact lenses is daily contact lenses, which can be worn for up to 12 hours, removing them before going to bed.

The advantages of hard contact lenses, especially those used during the day, should be mentioned the better oxygen access due to material with high gas permeability, smaller lens diameter and looser lens movement on the eye, and more tears get under the lens at blinking (in comparison, the soft lenses are very immobile and tears virtually not passing under the lens). Hard contact lenses also provide greater visual acuity as they are made individually based on corneal topography and other examination data; the lenses also retain the shape on eye regardless of external conditions (for example, soft lenses may change the shape and degrade visual quality if the eye becomes drier). Hard lenses can be used for longer time period – even up to 24 months at proper care; they are also more durable.

It is important to note that the choice of hard contact lenses requires longer adaptation; they should be worn every day to make them easier to get used to. In addition, wearing hard lenses is more likely to cause the lens to fall out during contact sports or rubbing the eyes. Sand and dust can get under the lens because the lens does not fit as tightly as it does with soft contact lenses. Since hard lenses are custom-made, you should be aware that they are slightly more expensive than soft lenses, so great care must be taken not to lose them.