Most people who need vision correction can wear contact lenses. An estimated 45 million Americans already do. The real question is whether your eyes, your vision needs, and your daily habits make you a good candidate, and that depends on several factors your eye doctor will evaluate during a contact lens exam.
Age Requirements and Children
There is no strict minimum age for contact lenses. The FDA approved the first contact lens designed to slow nearsightedness progression in children, with a recommended starting age between 8 and 12. In practice, readiness depends more on maturity than birthdate. If a child can handle basic personal hygiene responsibilities consistently, like brushing teeth without reminders and washing hands thoroughly, they’re more likely to manage the care contacts require.
Extended-wear lenses, the kind you sleep in, are generally not recommended for children and teens because they increase the risk of corneal ulcers. Daily disposable lenses are a safer choice for younger wearers since there’s no cleaning routine to forget.
Vision Conditions Contacts Can Correct
Contact lenses correct the same core vision problems that glasses do: nearsightedness, farsightedness, and astigmatism. Soft toric lenses are now widely available for people with astigmatism who previously had to rely on rigid lenses. If you’re over 40 and starting to lose your ability to focus up close (presbyopia), multifocal contact lenses let you see at multiple distances without switching to reading glasses.
There’s also a specialized option called orthokeratology, where you wear rigid lenses overnight to temporarily reshape your cornea and see clearly during the day without any lenses. These were FDA-approved in 2002 for correcting nearsightedness and are increasingly used in children to slow its progression, though that specific use remains off-label.
What Happens During a Contact Lens Exam
A contact lens prescription is not the same as a glasses prescription. Your eye doctor needs to measure your cornea’s shape, size, and curvature using instruments that analyze how light reflects off your eye’s surface. A keratometer measures a small area of the cornea, while a corneal topographer maps the entire surface in detail, producing a color-coded picture of any irregularities. These measurements determine the base curve and diameter of lenses that will fit your eye properly.
Your doctor will also measure your pupil or iris size to select the right lens diameter, then evaluate your tear film. This step is critical. One common test places a small strip of paper under your lower eyelid to measure tear production. Another uses a fluorescent dye to time how quickly your tears evaporate. If your eyes don’t produce enough tears or the tears break down too fast, wearing contacts may be uncomfortable or unsafe.
Once measurements are complete, you’ll try on trial lenses for several minutes. Your doctor watches how the lenses settle and interact with your tears and corneal shape, then checks your vision and comfort before finalizing the prescription.
Conditions That Can Disqualify You
Most medical contraindications for contact lenses are relative, meaning they don’t automatically rule you out but require careful evaluation. Severe dry eye syndrome is one of the most common barriers. If your eyes can’t maintain adequate moisture, lenses will feel gritty and irritating, and the friction can damage your cornea over time.
Other conditions that may prevent standard contact lens wear include chronic eye infections or inflammation, recurring corneal ulcers, abnormal eyelid positioning that interferes with lens fit, and certain corneal diseases that affect the surface’s clarity or shape. A growth of tissue extending onto the cornea (pterygium) or significant blood vessel growth into the cornea can also be problems. Chronic allergic eye conditions, particularly seasonal allergies severe enough to cause persistent redness and swelling, can make lens wear miserable.
Specialty Lenses for Difficult Cases
People who can’t wear standard soft contacts aren’t necessarily out of options. Scleral lenses, which are larger and rest on the white of the eye rather than the cornea, have expanded contact lens candidacy dramatically. They account for roughly 36 percent of specialty lens fittings for keratoconus alone, a condition where the cornea thins and bulges into a cone shape.
Scleral lenses vault over an irregular corneal surface, creating a smooth optical interface and a reservoir of fluid that keeps the eye constantly hydrated. This makes them effective for people with severe dry eye from autoimmune conditions, corneal scarring from injury or prior surgery, complications from LASIK or other refractive procedures, and inherited corneal diseases. For many of these patients, scleral lenses restore functional vision when nothing else works.
Options for People Over 40
Presbyopia, the gradual loss of near-focus ability that typically begins in your early to mid-40s, used to be the point where many contact lens wearers gave up and switched to reading glasses. Multifocal lenses have changed that. These lenses contain multiple prescription zones so you can see clearly at different distances.
The alternative is monovision, where one eye is corrected for distance and the other for close-up work. Your brain learns to prioritize the appropriate eye depending on the task. Monovision tends to work well for younger presbyopes and people with higher near-vision needs than multifocal lenses can handle. It’s also a practical solution for people with astigmatism, since multifocal toric lenses can be harder to fit.
Not everyone adapts well to either approach. If you have zero tolerance for any compromise in visual clarity, particularly at distance, contacts for presbyopia may frustrate you. Your eye doctor will typically discuss your priorities and daily visual demands before recommending one method over the other.
Lifestyle and Environment Factors
Your daily activities influence which type of contact lens works best, and whether contacts make sense at all. Athletes generally do well with contacts because lenses provide a wider field of vision than glasses and won’t fog up or fall off. Daily disposables are popular for active people since there’s no cleaning involved. You wear them once and throw them away, which also reduces infection risk in dusty or sweaty conditions.
Modern silicone hydrogel materials let significantly more oxygen reach the cornea than older hydrogel lenses. Earlier hydrogel materials couldn’t always deliver enough oxygen even for daytime wear, while silicone hydrogel lenses meet the oxygen requirements for both daily and extended wear. This advancement has made contacts viable for people who previously experienced discomfort or corneal swelling from insufficient oxygen transmission.
If you spend a lot of time outdoors, some contact lenses include built-in UV filtering, though they don’t replace sunglasses since they only cover the cornea, not the surrounding eye tissue.
Risks That Come With Wear
Contact lenses are safe when used correctly, but they do carry risks that anyone considering them should understand. Corneal infections from all causes, including contact lens wear, result in approximately 1 million clinic and emergency department visits per year in the United States. In a CDC review of over 1,000 infection reports tied to contact lenses, about 20 percent of patients ended up with a central corneal scar, decreased vision, or needed a corneal transplant.
The biggest modifiable risk factor is sleeping in lenses. Wearing contacts overnight increases infection risk six- to eightfold, even with lenses approved for extended wear. Other preventable behaviors flagged in the CDC data included wearing lenses past their replacement schedule (about 8 percent of cases), occasional napping in lenses (7 percent), and storing lenses in tap water instead of proper solution. Daily disposable lenses had the lowest share of infection reports at just 3.3 percent, compared to 57 percent for reusable soft daily-wear lenses and 35 percent for extended-wear lenses.
The takeaway is straightforward: nearly all serious complications trace back to hygiene shortcuts. Replacing lenses on schedule, never sleeping in them unless specifically prescribed, and using fresh solution every time you store them eliminates most of the risk.