Contact Lens - A Consumer Guide
Q: Is it safe to wear soft contact lenses during asleep?
A: Some soft contact lenses are approved for sleeping by the FDA. These lenses have been tested for safety, but it is vital to follow the rules as prescribed by your practitioner. It is not safe to sleep in daily wear lenses. Your eyes could experience permanent damage due to a lack of oxygen.
Q: Is it safe to order contact lenses online?
A: Contact lenses are a prescription medical device. By law, they cannot be sold without a valid prescription. There is nothing wrong with ordering lenses online as long as you have a valid, new prescription from your eye care practitioner and you are having regular check-ups to make sure your lenses are fitting well and your eyes are healthy. Do not let any contact lens company change the brand or type of lenses you are wearing.
Q: Is it safe to switch contact lens solution?
A: Each contact lens care solution has a different chemical makeup. Some use harsh preservatives that cause sensitivity and even allergy in a high percentage of users. Some can discolor a patient's contact lenses, making them useless. Sometimes the chemicals in one lens cleaning system can improperly combine with the chemicals in another system when they are used in combination, causing a reaction for the user.
Q: Is it safe to swim with the soft contact lenses in?
A: It is highly recommended to wear goggles if you swim with soft contacts on your eyes. There are nasty bugs living in swimming pools. One of them, called acanthameba, can cause horrible pain and damage to your eye. The water can change the way your lenses fit, making them too tight and causing severe eye health problems. So, either take them out for swimming or wear goggles. Or you can use one-day lenses.
Q: Why do some contact lenses feel drier than others?
A: Contact lenses are made from different plastics and silicones that have different characteristics. Some have more water content than others. All contact lenses are subject to evaporation while on the eye. The rate of this happening depends on many factors: humidity, wind, temperature, your health, what medicines you are taking, how much you blink, the care system you use, how clean the lenses are, etc. A few contact lenses are now available that are made from plastics that resist dehydration and evaporation.
Q: Why blood vessels grow into the color of the eyes?
A: When contact lenses are over worn, the cornea has been starved for oxygen during overnight wear. This oxygen deprivation stimulates the growth of new blood vessels (neovascularization) into the cornea where blood vessels usually do not exist. The farther into the cornea they grow, the more problematic they can be. When the contact lens wear is stopped, the blood vessel growth stops, but the vessels themselves remain, though the blood within them may disappear - so called ghost vessels. Depending on the severity of the neovascularization, resuming contact lens wear may not be possible.
Q: Why some people, wearing rigid gas permeable contact lenses, perceive irritation in their eyes after gusts of wind.
A: Unlike soft lenses, rigid gas permeable lenses are smaller than the cornea. They float on the tears, moving up and down with every blink. A gust of wind can blow dust and other airborne material into the tears, which then carry this material under the lenses upon blinking. This occurs less often with soft lenses since they are covering the entire cornea. Eye drops can help solve the problem.
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