Getting contact lenses involves more than picking up a box at the store. You’ll need a separate prescription from your glasses, a fitting exam tailored to your eye shape, and a basic care routine to keep your eyes healthy. The process is straightforward, but a few things are worth understanding before you commit.
Your Glasses Prescription Won’t Work
Contact lenses sit directly on the surface of your eye, while glasses sit about 12 millimeters away. That distance changes how light bends before it reaches your retina, so the corrective power of each lens is calculated differently. Even if you already wear glasses, you’ll need a contact-specific prescription.
A contact lens prescription includes two measurements your glasses prescription doesn’t: the base curve, which matches the curvature of the lens to the shape of your eye, and the diameter, which determines how much of your eye the lens covers. These numbers matter for comfort and fit. Using the wrong base curve can cause the lens to slide around or press too tightly against your cornea.
What Happens at a Fitting Exam
A contact lens fitting is a separate appointment from a standard eye exam, and it typically costs extra. Your eye doctor will measure the curvature of your cornea, the size of your iris and pupil, and your tear production. That last part is important: contacts float on a thin film of tears throughout the day, and if your eyes are too dry, standard lenses may not be an option. In mild cases, your doctor can recommend lenses designed for drier eyes.
After measurements, you’ll get a trial set of lenses placed on your eyes in the office. The doctor checks your vision, evaluates how the lens sits on your eye, and adjusts the prescription if needed. You’ll then take home a five to ten day supply to wear in your normal routine. This trial period matters because a lens that feels fine in the office can behave differently after a full day of screen time, driving at night, or being outdoors in wind.
A follow-up visit is scheduled toward the end of that trial. Your doctor will look for any irritation, check for deposits on the lens surface, and fine-tune your prescription for situations like reading, computer work, or low-light driving. Only after this follow-up is your prescription finalized.
Types of Lenses and What They Correct
Most first-time wearers end up in soft lenses, which come in two main materials. Older-style hydrogel lenses have higher water content but let through less oxygen. Newer silicone hydrogel lenses, developed in the late 1990s, allow significantly more oxygen to reach your cornea. That extra oxygen helps prevent corneal swelling, especially if you tend to wear your lenses for long hours. Almost all modern soft lenses use silicone hydrogel.
If you have astigmatism (where your cornea is slightly oval-shaped rather than round), you’ll need toric lenses. These are weighted to stay in the correct orientation on your eye, since the lens power varies across different angles. If you’re over 40 and struggling with both distance and close-up vision, multifocal contacts combine both corrections in a single lens, similar to progressive glasses.
For people with very irregular corneas, hybrid lenses combine a rigid center with a soft outer ring. Rigid gas-permeable lenses are another option, offering sharper vision for certain prescriptions, though they take longer to adapt to.
Daily vs. Monthly: Cost and Convenience
Daily disposable lenses are single-use. You open a fresh pair each morning and throw them away at night, which eliminates cleaning and storage entirely. Monthly lenses are worn during the day, cleaned each night, and replaced after 30 days. There are also two-week replacement schedules that split the difference.
Daily lenses typically run $25 to $40 for a box of 30, or $55 to $90 for a box of 90. That works out to roughly a dollar per lens. Monthly lenses cost about $30 to $40 for a six-pack, or $3 to $4 per lens. If you wear contacts every day, monthlies are noticeably cheaper over a year. But if you only wear contacts three or four days a week (for sports, social events, or alternating with glasses), the annual cost of dailies and monthlies comes out about the same.
Dailies also carry the lowest infection risk of any lens type. Monthly and extended-wear lenses accumulate protein deposits and bacteria over their lifespan, which is one reason replacement schedules exist.
How to Clean and Store Lenses Safely
If you wear reusable lenses, you have two main cleaning systems: multipurpose solution or hydrogen peroxide-based solution.
- Multipurpose solution cleans, rinses, disinfects, and stores your lenses in one step. Rub and rinse your lenses with fresh solution every time you remove them. Never “top off” old solution in your case with a splash of new solution, as this dilutes the disinfectant and lets bacteria survive. After emptying the case, rinse it with fresh solution (not water), then store it upside down on a clean tissue with the caps off to air dry.
- Hydrogen peroxide systems use a special case that neutralizes the peroxide into saline over four to six hours. You must use only the case that comes with the system. Putting lenses soaked in un-neutralized peroxide directly into your eyes causes intense stinging and pain. These systems tend to clean more thoroughly and work well for people sensitive to the preservatives in multipurpose solutions.
Water and Contact Lenses Don’t Mix
This is the rule most new wearers don’t expect: contact lenses should never touch water. Not tap water, not pool water, not shower water. The CDC specifically warns against wearing contacts while swimming, showering, or using a hot tub. Water, even treated tap water, contains microorganisms that can cling to a contact lens and cause serious eye infections.
The most dangerous of these is an amoeba called Acanthamoeba, which is commonly found in tap water, lakes, wells, and hot tubs. It can cause a painful corneal infection that’s notoriously difficult to treat. If water does splash onto your lenses, remove them as soon as possible. Throw away daily lenses, or clean and disinfect reusable lenses overnight before wearing them again.
Infection Risk by Lens Type
The most common serious complication from contact lens wear is microbial keratitis, a bacterial or fungal infection of the cornea. Your risk depends heavily on how you use your lenses. Extended-wear lenses approved for overnight use carry the highest rate: about 2.5 cases per 10,000 wearers per year. Extended-wear lenses used only during the daytime drop to 0.76 per 10,000. Daily disposables have the lowest rate at 0.62 per 10,000.
Sleeping in contacts is the single biggest risk factor, even for lenses marketed as safe for overnight wear. The closed eyelid already reduces oxygen flow to your cornea, and a contact lens reduces it further, creating conditions where bacteria thrive. If you know you’ll occasionally fall asleep in your lenses, talk to your doctor about which lens material gives you the most margin of safety.
Conditions That May Complicate Lens Wear
Most medical issues that affect contact lens wear are manageable rather than absolute deal-breakers. Chronic dry eye is the most common concern, since lenses can worsen dryness and become uncomfortable by midday. Chronic allergies that affect the eyes, recurring eyelid inflammation, and a history of corneal ulcers or infections all require extra caution. A growth on the white of the eye called a pterygium can also interfere with lens fit.
None of these conditions automatically disqualify you. Your eye doctor will weigh the severity and may recommend specific lens types, wearing schedules, or supplemental eye drops that make lens wear possible. The fitting exam is designed to catch these issues before you commit to a purchase.
What the First Few Days Feel Like
Putting a contact lens in your eye for the first time feels strange. You’ll blink more than usual, and your instinct will be to close your eye or pull away. Most people get comfortable with insertion and removal within three to five days of practice. Your eye doctor’s office will teach you the technique before you leave with your trial lenses, and many offices won’t let you leave until you can do it yourself.
During the trial period, you may notice the lens edges occasionally, especially when you blink or look to the side. This is normal and usually fades as your eyelids adapt. What isn’t normal: persistent redness, pain, blurred vision that doesn’t clear when you blink, or a feeling that something is stuck under the lens. These are signs the fit, material, or your eye’s response needs to be reassessed at your follow-up.