Rigid oxygen permeable contact lens information
Introduction
Contact lenses rest on the cornea, which is the transparent tissue that makes up the front surface of your eye. The cornea has a high metabolic rate (high energy requirements) and therefore requires an adequate supply of oxygen to maintain its normal health. The major source of oxygen to the cornea is from the air via the tears. All contact lenses will reduce the flow of oxygen to the cornea to some extent.
With hard contact lenses in the past, the material (PMMA) did not allow oxygen to flow through the lens. The supply of oxygen to the cornea depended on tear exchange underneath the lens movement with blinking. If insufficient oxygen reached the cornea, edema (swelling) would occur. This swelling caused such side effects as spectacle blur (poor vision with glasses following contact lens wear), and over long periods of time, corneal distortion.
Oxygen permeable contact lenses differ from conventional hard lenses, as the material does allow oxygen to diffuse through the lens itself. Therefore, there are two sources of oxygen: 1) permeability through the lens; 2) tear exchange. With oxygen permeable lenses clear vision with glasses is achieved after contact lens wear.
These lenses are rigid, therefore, patients with corneal astigmatism can successfully wear oxygen permeable contact lenses.
1) Wash your hands with a mild (non-cosmetic) soap. Rinse your hands thoroughly and dry with a lint- free towel.
2) Close drain if working over a sink to prevent possible lens loss. A flat work area is preferable and a mirror may be placed on the surface.
3) To avoid confusion, always start with you right lens. (Note: The right lens usually has a dot at the outer edge.)
4) To remove your lens from the case, gently place your index finger on the center of the lens and slide it out of the case. (Note: the lens should always be stored in soaking solution.)
5) After removing the lens from the case, lens to be sure it is clean and undamaged. Never place a damaged lens on your eye.
Lenses Placement
1) After inspection place the lens on the tip of the index finger of the right hand. Apply 1 drop of the wetting solution into the concave (cupped) side of the lens.
2) With head positioned directly over the mirror, look down and lift upper lid with forefinger of the left hand at the base of the eye lashes, press against the bony margin of the brow.
3) Look ahead and gently pull down lower lid with middle finger of the right hand.
4) Keep looking straight ahead (directly at own eye if using a mirror) and gently place the lens on the center of your eye. Upon contact the wet surface of the lens is naturally attracted to the tears on your eye. There is no need to press the lens against your eye during placement.
5) Slowly release the lower lid first, look down then very slowly let the upper lid down over the lens. If the lens is off center, follow steps in ”Reentering”.
6) Follow same procedure for the left lens but use opposite hands.
7) After placement of both lenses, discard the solution left in the case, rise with water, and let the case dry.
Infrequently a lens may be displaced onto the white of the eye during lens placement, removal, or lens wear. If this happens there may be some discomfort but not be alarmed. It is impossible for a lens to slip behind the eye. Locate the lens by gently pulling the lids as wide apart as possible, while looking into a mirror. Look in all directions to the extremes of gaze.
Having located the lens:
If the lens is off-centered to the right or left of the cornea look straight ahead and hold the lids apart with both hands. Gently guide the lens below the cornea by using your finger and then use your lower lid to move the lens up onto the cornea; or Use your lower lid to move the lens back over onto the cornea by placing gentle pressure on the lid with your finger.
If the lens is decentered upward hold your upper lid downward. If possible have someone check if they can see the lens. Keep looking downward and gently massage your upper lid downward to shift the lens back onto the cornea.
DO NOT use your fingernail to move the lens.
LENS REMOVAL
1) First wash and dry hands thoroughly.
2) Bend head over work surface and look straight ahead.
3) To remove the right lens, cup your left hand under your eye. Place the index finger of your right hand at the outer corner of your eye.
4) While looking into the palm of your hand, open your eye as widely as possible. Pull both lids simultaneously up and out towards your temple and blink the lens out from your eye into your hand.
5) Before changing position, be sure the lens is in the palm of your hand; not on your eyelashes.
6) Proceed to clean and store the lens.
7) Other methods of removal may be recommended by your optometrist.
Daily cleaning is necessary to remove filmy deposits and mucus, which can form on the lens through normal wear. Clean lenses contribute to comfort and good vision. Daily disinfection is necessary to help ensure good eye health.
1) Wash hands prior to handling your lenses.
2) Place the lens in the palm of your hand and apply a few drops of the recommended cleaner.
3) With the index finger of your other hand gently run the lens in a circular motion for 10 seconds.
4) Rinse the lens with water, (lukewarm to cold only) then with soaking solution.
5) To store your lenses place the lens concave side up in the appropriate compartment of your storage case. Fill the compartment with enough of the soaking solution to completely over the lens.
6) Lenses should be stored in the soaking solution for the time period specified on the label to ensure complete disaffection.
WEARING SCHEDULE
It is important to build up your wearing time slowly to allow your eyes to become adapted to your oxygen permeable lenses and reach optimal comfort. Do not
1) Annual eye examinations are required to ensure continued success with your contact lenses.
2) Gas permeable contact lens should not be worn all waking hours because they limit the amount of oxygen to the eye. Your optometrist will discuss an appropriate wearing schedule.
3) Up-to-date glasses are necessary for those periods while not wearing your contact lenses.
4) As light sensitivity will be increased with your contact lens, sunglasses may be required.
5) As dust or debris may become trapped under the lenses, try to avoid dusty conditions. If the lens irritates, use a comfort drop or clean the lens.
6) Do not swim with your gas permeable contact lenses, as the risk of loss is high.
7) Use the prescribed solutions as they are necessary for maintaining the wettability of the lens which will be reduced with water.
