Contact lens facts for kids
A contact lens is a tiny, thin lens that you place directly on the front surface of your eye. It sits on your cornea, which is the clear front part of your eye. Contacts can help you see better (these are called corrective lenses) or change the color of your eyes (these are called cosmetic lenses).
The most common type of contact lenses today are soft lenses. They were invented in 1961 by a smart Czech scientist named Otto Wichterle (1913–1998).
Contact lenses are usually made from special plastics called polymers. Many of these materials are "hydrophilic," meaning they absorb water. This helps oxygen reach your cornea, making the lenses more comfortable to wear. Older hard contact lenses were made from a material called PMMA, but newer ones are called rigid gas-permeable (RGP) lenses.
Some contact lenses have strong colors to change the color of your iris. These are used for fun or fashion. Other standard contact lenses have a very light color. This tint helps you see the lens better when you are putting it in or taking it out.
Contents
How Corrective Contact Lenses Work
Corrective contact lenses help people see clearly. An optometrist (an eye doctor) can figure out the exact strength you need. This strength is measured in "dioptres." The thickness and shape of your contact lens will depend on your eye condition.
Contact lenses can help with different vision problems:
- Nearsightedness (myopia): When you can see close objects clearly, but distant objects look blurry.
- Farsightedness (hypermetropia): When you can see distant objects clearly, but close objects look blurry.
- Astigmatism: When your eye has an uneven curve, causing blurry or distorted vision at all distances.
The idea of putting a lens directly on the eye was first thought of by René Descartes in 1636. However, the first successful contact lens was made much later, in 1887. It was created by a German scientist named Adolf Eugen Fick.
Special Lenses for Astigmatism
If you have astigmatism, you might need a special type of contact lens called a Toric lens. These lenses are made from similar materials as regular contacts. However, they have a few important differences:
- They have two different strengths built into them. One strength corrects for your overall vision problem (nearsightedness or farsightedness). The other strength corrects for your astigmatism.
- They are designed to stay in the correct position on your eye. Toric lenses often have a slightly heavier bottom. This helps them rotate back into place if they shift when you blink or move your eye. They might also have tiny marks to help you put them in correctly.
Cleaning Your Contact Lenses
It's super important to clean and disinfect your contact lenses regularly. This keeps your vision clear and helps prevent eye infections. Here are some common products used for lens care:
- Saline solution: This is a simple salt water solution. You use it to rinse your lenses after cleaning them. It also prepares them for putting into your eyes.
- Daily cleaner: This liquid is used to clean your lenses every day. You usually put a few drops on the lens and gently rub it for about 20 seconds. Always check the directions on the bottle.
- Multipurpose solution: This is a versatile solution that can do many jobs. It can be used for rinsing, disinfecting, cleaning, and storing your lenses. Many people use it mainly for disinfecting and storing their contacts overnight.
- Hydrogen peroxide solution: This solution is very good at disinfecting lenses. However, it's crucial to rinse lenses taken from hydrogen peroxide with another solution, like saline, before putting them in your eyes. This is because hydrogen peroxide can sting your eyes.
- Enzymatic cleaner: This cleaner helps remove protein buildup from your lenses. Proteins from your tears can stick to the lenses over time, making them uncomfortable. Enzymatic cleaners often come in tablet form and are usually used once a week.
Some contact lens solutions contain preservatives. However, about 10% of people who wear contacts have problems with these. Because of this, many brands now offer "preservative-free" products, often labeled "for sensitive eyes." Solutions without preservatives usually have shorter expiration dates once opened. For example, a preservative-free saline solution might only last two weeks after you open it.
Images for kids
-
A pair of contact lenses, positioned with the concave side facing upward
-
One-day disposable contact lenses with blue handling tint in blister-pack packaging
-
Artist's impression of da Vinci's method for neutralizing the refractive power of the cornea
-
In 1888, Adolf Gaston Eugen Fick was the first to successfully fit contact lenses, which were made from blown glass
-
Woman wearing a cosmetic type of contact lens; enlarged detail shows the grain produced during the manufacturing process. Curving of the lines of printed dots suggests these lenses were manufactured by printing onto a flat sheet then shaping it.
-
Scleral lens, with visible outer edge resting on the sclera of a patient with severe dry eye syndrome
-
Contact lenses, other than the cosmetic variety, become almost invisible once inserted in the eye. Most corrective contact lenses come with a light "handling tint" that renders the lens slightly more visible on the eye. Soft contact lenses extend beyond the cornea, their rim sometimes visible against the sclera.
-
Diameter and base curve radius
-
Inserting a contact lens
-
Young woman removing contact lenses from her eyes in front of a mirror
-
Lens case to store contacts
-
Contact lenses soaking in a hydrogen peroxide-based solution. The case is part of a "one-step" system and includes a catalytic disc at the base to neutralise the peroxide over time.
-
Christopher Lee as the title character in Dracula (1958) in one of the first uses of contact lens with makeup in films
See also
In Spanish: Lente de contacto para niños
