Understand expiration dates of contact lenses

You are using contact lenses but do not know how long you should use them and the harmful effects of wearing expired contact lenses. Let’s check out the following article of Caras lens to find out the answers about the shelf life of contact lenses nowadays.

1. How long can contact lenses be used?

Contact lenses have 2 types of expiration dates that you must know: the term before opening the seal and the term after opening the seal. So how long can contact lenses be used for?

1.1. Expiration date of the lens before unsealing

The expiration period before opening the seal is the one printed on the product’s packaging. Usually, the expiration date of contact lenses before unsealing will be from 5 to 6 years.
The shelf life of contact lens soaking solutions and eye drops will be 3 years.

1.2. How long can contact lenses be used after opening?

After being unsealed, the shelf life of the lens will range from 6 months to 1 year. However, we recommend you to use contact lenses for only around 50% of the maximum shelf life of the lenses from the time of opening the package, to experience the softness and best quality of the lenses.
That means if the expiration date of the contacts is 1 year, you should only use them within 4-6 months, then replace them with a new pair.

1.3 How to know if you are unfortunately using expired lenses.

If you forget the expiration date of your lenses, you might encounter the following problems:

• Eyes are red and irritated.
• Vision is not good, there is an abnormal change in vision
• Eyes get hurt and discomfortable when wearing for a period of 3-4 hours.

If you experience any of the above problems, you should discards the lenses immediately! Check out Caras’s way of taking out contact lenses safely to protect your healthy eyes.
In order not to have any bad experiences for your eyes, periodically check the expiration date. If you don’t remember you can check the following information:

• The brand you bought your contact lenses from
• Material of contact lenses.
• the amount of time you used them in a single day

From that, you can find out the expiration date of the lens. Especially if you buy lenses at Caras, we will send an email to remind you of the expiration date of your contact lenses 7 days in advance, so you can discard them or buy yourself a new pair of lenses.

2. The difference among 1-day, 3-month and 6- month contact lenses

Regardless of whether it is 1-day, 1-month contact lenses or 6-month, 1-year contact lenses, their shelf life is calculated from the moment when the packaging is open.
When it reaches the expiration date, although the appearance of the lenses look no different that much, you cannot continue to wear them anymore.
Because after opening, the material of the contacts has begun to age, the surface also begins to be invaded by germs, dirt; as well as substances secreted by the eyes will stick to the contacts.
If you continue to wear it, it is easy to cause eye diseases, so you should change your contact lenses on time.

What if you forget the purchase date and the date you open the packaging? The simplest way is to check if you still feel comfortable when wearing them.
If after a while, you feel that your eyes are itchy and uncomfortable, you must definitely throw that pair of lenses away. Never cry over them, otherwise your eyes will be hurt.
Each type of contact lenses with different shelf life will have a different processing technology to increase their durability, while their designs or materials will be the same.
The longer the shelf life of contact lenses is, the more resistant the lenses are to repeated washing and the harder they get torn, and less likely to be dirty as well.
In contrast, 1-day contact lenses will be processed to be thinner ones which are easy to tear and easy to get stained, so they are only used once and must be discarded immediately.
Therefore, you should consider choosing 1-month, 3-month, 6-month or 1-day contact lenses to suit your individual needs.

3. The risks of wearing expired contact lenses

In your opinion, what are the harmful effects of wearing contact lenses in the wrong way?
Below are some harmful effects of wearing expired contact lenses that you must know:

• Allergic reactions: there is always a certain amount of protein in the structure of contact lenses. So if you let your lenses expire, these proteins can make your eyes irritated, itchy, and dry.
• Conjunctivitis: The amount of protein in the lenses will attract bacteria which easily cause conjunctivitis. Some common symptoms are red eyes, itching, blurry vision, etc.
• Corneal swelling (or bulging): Expired contact lenses reduce the oxygens that need to supply to the cornea, and at the same time there is an increase in the amount of mucus that causes blurry vision or dark circles around the eyes.
• Neovascularization – condition of the cornea without blood vessels: When there is a lack of oxygen, the eyes will automatically create a mechanism to grow blood vessels in the hope of increasing oxygen for the eyes. However, the growth in the number of blood vessels will affect your vision negatively. On top of that, these blood vessels are extremely weak, it might make you bleed leading to blindness at any time.
• Corneal abrasion / corneal ulcer: Again, because of the shortage of oxygen, the corneas and cells of the eyes become weaker and vulnerable. The scratched cornea leading to infection can cause very dangerous complications including blindness.

These complications can occur if you do not comply with the usage time of the lenses. So consult your doctor and carefully learn the expiration date of your contact lenses.
So how long can contact lenses be used in a single day? Let’s check it out with Caras!

4. How many hours a day should I wear contact lenses?

The maximum amount of time to wear contact lenses is from 3 to 8 hours a day. Do not wear contact lenses for too long. This is a reasonable and safe amount of time for eyes, to avoid dry, red eyes.
During this time, you will enjoy the functionality and convenience in a complete way that the contact lenses bring to you. Avoid wearing contact lenses while your eyes are resting (take a nap or sleep at night).
For those, who have to use them for longer than the number of hours mentioned above, it is recommended that you remove the lenses while resting and soak the lenses in the cleaning solution. About 30 – 60 minutes later, you can use them again. This is the best way to provide your eyes and the lenses with proper rest.
Caras’s recently received a lot of questions about how often to instill eyedrops when wearing contact lenses. You will probably have the same question.

4.1 How often to use eyedrops with contact lenses

In case, you do not have problems with dry and itchy eyes when using lenses but have to wear lenses for a long time, do not forget to use eye drops often! You should bring eye drops with you, instill 1-2 drops each time about every 2 hours while wearing contact lenses or when you feel your eyes dry.

4.2 How long can you wear the 1- day contact lenses?

So how long can you wear 1-day contact lenses? Especially, for the 1-day lenses, you should only use them once and it is best to use them for a maximum of 8-10 hours, do not reuse them.
With USA technology – Antibacterial, super breathable, and hydrated, Caras 1-day lenses on the market have a usage time of up to 24 hours. However, if possible, you should use them for 10 hours as the longest to give your eyes time to rest and keep them healthy!

How many hours a day is best to wear contact lenses?

Wearing contact lenses prior to expiry is an effective way to protect your beautiful eyes, so pay attention to the expiration date of your contact lenses and how long you should wear them.
If you want to learn more about contact lenses and relevant questions, you can follow our Blog. Hope you can choose a good and suitable pair of contact lenses in terms of aesthetics and quality at Caraslens.