A contact lens is a very thin, curved piece of lens that is placed in front of the cornea (front of the eye) to correct refractive errors: nearsightedness, farsightedness and astigmatism.
Advantages of contact lenses
Contact lenses bring a number of benefits to the patient who wears them. For example:
- They allow you to appreciate a total visual field, something that does not occur using glasses, where the visual field is limited by the frame.
- There are no lateral distortions, since the lenses move with the eye, providing good vision in all gaze positions. This is not the case with spectacles where, in lateral positions, the patient may have distorted vision.
- Contact lenses do not fog up or become misaligned like glasses.
- They can allow the patient a full prescription tolerance if they have a difference in prescription between the two eyes.
- If the patient practices any sport, it will always be more comfortable, especially if it is a contact sport where he/she cannot wear glasses.
- They provide better esthetics.
What types of contact lenses are there and how often should they be replaced?
Depending on the material they are made of, there are different types of contact lenses: semi-rigid, soft and hybrid.
Soft contact lenses are made of hydrophilic (water-absorbing) plastic. They are the most commonly used because of their comfort. Within soft contact lenses there are two main groups: hydrogel and silicone hydrogel. The latter is the lens that transmits more oxygen to the eye and, therefore, the most recommended in most cases.
Semi-rigid contact lenses are made of rigid plastics. They are currently used in more specific cases such as high refractions and/or irregular corneas.
In hybrid contact lenses, used in very specific cases, the center is like a semi-rigid contact lens and the periphery is like a soft lens. They are used in patients who need the benefits of the semi-rigid lens and cannot tolerate them because of the discomfort involved.
There are also different lenses depending on their replacement. Soft contact lenses range from daily replacement (wear and tear) to annual replacement. As a general rule, and for hygienic reasons, soft contact lenses are usually replaced daily and monthly. In contrast, semi-rigid contact lenses are usually replaced annually.
How should contact lenses be maintained?
Contact lens care and maintenance is very important. By following these recommendations, your contact lenses will remain in top condition:
- Wash and rinse hands thoroughly before handling any contact lens.
- Use the maintenance liquid recommended by the Ophthalmology specialist to preserve and clean the lenses when they are not in the patient’s eyes. Never use water or other liquids.
- It is also very important to clean the lens holder, which should be replaced every 3 months.
- Depending on the contact lens and the ocular surface, it is necessary to use a specific type of solution to be decided by the specialist.
Frequently asked questions about contact lenses
- Can I wear contact lenses if I have astigmatism? Yes. In the examination with the optometrist a topography is performed to check the state of the cornea and to be able to make a personalized adaptation, according to the eye and its refraction. Patients with high astigmatism usually have better vision with semi-rigid contact lenses.
- Can I use multifocal contact lenses? Probably. Nowadays there are multifocal contact lenses with a wide variety of prescriptions and parameters to fit most eyes. It is advisable to have a previous check-up to check if the patient has a good eye health and then start with the adaptation. It is assessed that the lens is well placed in the eye and that the distance, near and intermediate vision are good.
- Can I wear contact lenses if I have dry eye? Yes, but it is recommended that the patient’s tear film be evaluated beforehand to determine the reason for the patient’s dry eye and to be able to offer specific contact lenses for patients with dry eye. In these cases, when contact lenses are used, it is advisable to combine them with artificial tears to increase comfort, since good hydration is essential to maintain the elasticity and transparency of the eye.
- From what age can my child wear contact lenses? There is no set age for fitting contact lenses. It is something that depends entirely on the child’s skills to make a good manipulation and maintenance of the lenses. In these cases, parents and children should be taught the guidelines to follow and adult supervision at home is advised during the first few months. During the first few years of lens wear, it is recommended to increase the frequency of check-ups.
- Can I wear contact lenses in the office? No. Being in front of the computer interferes with the frequency of blinking, decreasing it. If the patient wears contact lenses when he/she is in front of the computer, it is very likely that he/she will feel dry eyes. The advice in these cases would be:
- Humidify the office or work area with humidifiers.
- Increase the frequency of conscious blinking.
- Moisten contact lenses with compatible artificial tears.