Contact lens care
For contact lens care, it is important to be cleaned, rinsed, and disinfected every day.
1. Cleaning: Different cleaning solutions should be used for different types of glasses. To clean soft lenses, place the lenses in the palm of your hand, shake the cleaning solution well, and add one or two drops to the lenses, rubbing them back and forth with your middle finger to clean the dirt on the mirror surface. After cleaning one side, reverse the lens to clean the other side, it takes one to two minutes to clean one lens. When cleaning hard lenses and oxygen-permeable hard lenses, hold the lens with the cleaning solution and rub it with your index finger and thumb, so that both sides of the lens can be cleaned at the same time.
2. Rinse: The purpose is to completely flush out the cleaning solution that can damage the eyes. Rinse the lenses with bottled saline, not with homemade saline or tap water. Place the lens cleaned with the cleaning solution in your palm, add the saline, and rub it with your middle finger to flush out all the cleaning solution.
3. Disinfection: after rinsing, the lenses should undergo a disinfection procedure before they can be worn. The disinfection procedure for hard lenses and oxygen-permeable hard lenses is relatively simple and involves simply placing the lenses in a storage solution. Disinfection of soft lenses is more complex, with the following three methods:-
- Thermal disinfection method: The cleaned and rinsed lenses are placed in the case, saline is added, and the entire case is heated to 80 degrees Celsius for 15 minutes to complete the disinfection process. After the heat has dissipated, the lenses are ready for use. The advantage is that it is very effective and since only saline is used, it does not cause eye irritation and discomfort. The disadvantage is that the heat will cause some damage to the lenses, which will shorten the life of the lenses and they should be replaced within a year.
- Hydrogen peroxide disinfection method: disinfect the cleaned and rinsed lenses by putting them in hydrogen peroxide. Hydrogen peroxide can damage the eyes, so after disinfection with hydrogen peroxide, the lenses must undergo a neutralization process before use. Neutralization can be done with a neutralizing pill or a neutralizing metal ring. The time required for disinfection with hydrogen peroxide and the time required for neutralization can vary from tens of minutes to several hours. The advantage is that if the hydrogen peroxide is completely neutralized, it is not likely to cause eye irritation. The disadvantage is that the procedure is complicated and includes both disinfection and neutralization, without which one cannot be used, and the lenses should never be used until the neutralization is complete.
- Chemical disinfection method: the cleaned and rinsed lenses are placed in a disinfectant solution and the chemical components of the solution are allowed to disinfect the lenses, which usually takes 4 to 6 hours. The advantage is that it is simple and, if necessary, the lenses can be removed from the solution and put on the eyes immediately. The disadvantage is that during the disinfection process, the chemicals in the solution can leach into the lenses. When the lenses are placed freshly on the eyes, the chemicals can leach out of the lenses and some people can be sensitive to these chemicals and causing discomfort.
- Protein Removal: In addition to the daily cleaning, rinsing, and disinfection procedures, oxygen-permeable hard lenses are subjected to a weekly protein removal procedure. The cleaned and rinsed lenses are immersed in saline for 20 to 40 minutes, then the lenses are removed and rinsed once, and the disinfection process continues. The purpose is to remove protein deposits from tears, which is very important for eye health, especially for those who choose the heat disinfection method, which must be done weekly. The heat causes a chemical reaction with the clear proteins previously accumulated on the lenses, forming a white, opaque alternative protein. This can cause permanent damage to the lenses.
How to choose a contact lens care system
As with contact lenses suppliers, it is important to consult an optometrist to choose a suitable care system.
- The treatment of hard and oxygen-permeable hard lenses is relatively simple and consistent, and there are no multiple care systems to follow.
Soft lens users who are sensitive to chemical disinfectants can switch to hydrogen peroxide or thermal disinfection.
- Thermal disinfection can cause some damage to the lenses, especially for some long-wearing lenses.
- If you have difficulty in handling the complicated procedures of hydrogen peroxide disinfection, you can use the simpler chemical disinfection method.
- Some soft lenses are colored, and hydrogen peroxide can bleach the color, so colored lenses should not be disinfected with hydrogen peroxide.
Contact lens classification (1): Types of lenses
| Category | Nature | Advantages | Disadvantages |
| Hard Lenses | l Oxygen impermeable l Made of acrylic film | l Hard: not easily deformed, broken, and worn l More durable l Less chance of bacteria growth | l Short wearing time, 8 hours per day l Easier to slip away from the cornea, causing discomfort and blurred vision |
| Oxygen-permeable rigid lenses | l Oxygen permeable l Made of oxygen-permeable adhesive material | l Longer wearing time than rigid lenses, 12 to 14 hours per day l More stable on the cornea than rigid lenses, with less chance of slipping away from the cornea and causing discomfort, but still less stable than soft lenses | l More fragile l Easier to accumulate dirt and wear l Care procedures are more complex than for hard lenses |
| Soft lenses | l Oxygen permeable l Made of water-absorbent adhesive material l The thinner the lens or the higher the water content, the higher the oxygen permeability | l Comfortable and easy to adapt l Longer wearing time, 12 to 16 hours per day l Very little chance of slipping off the cornea and causing discomfort | l Harder to detect problems such as chipped lenses l Easier to break by fingernails l More complicated care procedures and prone to bacterial growth l Shorter life span, need to be replaced in a year to a year and a half |
Contact lens classification (2): wearing time
| Category | Wearing time | Lens Features |
| Daily wear lenses | l 12 to 16 hours per day | l Cannot be worn to sleep l Can be hard lenses, oxygen-permeable hard lenses, or soft lenses |
| Long wear lenses | l Varies from person to person: from daily removal to 7 days of continuous wear | l High oxygen permeability, some people can sleep with them l Can be oxygen-permeable hard or soft lenses |
| Disposable contact lenses (including one-day, two-week, and one-month disposable types) | l Varies from person to person: from daily removal to 7 days of continuous wear | l High oxygen permeability, some people can sleep with them l Each pair of lenses should be discarded and replaced after only one day to one month: up to one month for those who remove and clean them daily, and every week for those who wear them for 7 days in a row l Must be soft lenses |
How to choose contact lenses
The choice of general eyeglasses can be based on personal preference. To choose the right contact lenses, you must have an eye examination by a registered optometrist and then make an individual choice based on your needs. The following are some general observations.
- Basically, hard lenses should not be considered because they are not oxygen permeable. As for the choice of oxygen-permeable hard or soft lenses, it varies from person to person and should be in line with the three principles of health, comfort, and clear vision.
- Try to use daily wear glasses. If you choose to wear long lenses, you should remove them daily when you go to bed. Because of the long-term non-stop wearing of contact lenses, there will be adverse effects on the eyes.
- For users who have irregular work schedules or need to wear lenses for 24 hours continuously, consider using long-wear lenses, but you must consult your optometrist and try to take them off at bedtime.
For soft lens users, disposable contact lenses are more suitable but more expensive.
- For those who love sports, soft lenses should be used. If you use hard lenses or oxygen-permeable hard lenses, the lenses will easily slip away from the cornea and even detach from the eyes. In addition, if the eye is accidentally injured during sports, the degree of damage caused by soft lenses is also smaller.
