It's time, yet again, to check your medicine cabinet for your eye drops. 

Last week, more than two dozen eye drops were voluntarily recalled -- which included which included CVS, Rite Aid, Target and other brands -- by their manufacturer, Kilitch Healthcare India Limited, for potential safety reasons. 

The US Food and Drug Administration in October warned people not to purchase these eye drops because they could cause eye infections leading to "partial vision loss or blindness" following an investigation that found bacteria and "insanitary conditions" in the manufacturing facility. 

Kilitch said it hasn't received any reports of adverse events linked to the drops as of now, but people should stop using them and may return them to the place they were purchased. If you have symptoms of an eye infection, you should see a doctor.

Also this week, the FDA issued a warning letter to Amazon over some brands of eye drops sold online. The letter to Amazon says that seven types of eye drops -- Similasan Pink Eye Relief, The Goodbye Company Pink Eye, Can-C Eye Drops, Optique 1 Eye Drops, OcluMed Eye Drops, TRP Natural Eyes Floaters Relief and Manzanilla Sophia Chamomile Herbal Eye Drops -- are drugs that need FDA permission to be sold because they're marketed to treat specific health problems, like pink eye or eye irritation. 

An Amazon spokesperson said in a statement that the company has removed the eye drops from the online store.

"We require all products offered in our store to comply with applicable laws and regulations," the spokesperson said. "The products in question have been investigated and removed."

The FDA issued similar warning letters in September over some eye drops from CVS and Walgreens, along with other brands, either due to their FDA-unapproved marketing or their use of silver as a preservative.

Several other brands of artificial tears and eye drops have been recalled this year over various concerns, including bacterial and fungal contamination, lack of sterility and unsafe preservatives. Artificial tears from EzriCare and Delsam Pharma, for example, were associated with an antibiotic-resistant strain of bacteria that can cause eye infections.

But there are still safe eye drops out there, and they can ease a handful of symptoms. Here's what to know about shopping for and applying eye drops safely. 

How to shop for eye drops safely

Eye drops are used to treat a host of conditions, from minor irritants to chronic vision problems. Optometrists and ophthalmologists prescribe them to help patients heal after surgeries and to prevent infections. You can buy many of them over the counter to deal with dry eyes or an allergy flare-up. 

With so many options available, careful research is critical to ensure you choose the right eye drops to treat your particular eye issues. Ingredients vary widely by the type of eye drop, and using the wrong type of drop can cause more problems than it solves. 

Types of eye drops

Some eye drops can be purchased over the counter, while others require a prescription. The most common eye drops include:

• Lubricating drops: Also known as artificial tears, these are designed to relieve dryness and any associated redness or irritation. Common active ingredients include polyethylene glycol and propylene glycol. The nighttime version of these drops is thicker and comes in a gel or ointment.
  
• Anti-allergy drops: Antihistamine drops relieve itchiness, redness and other irritation resulting from reactions to allergens like pollen or pet dander. There are several options on the market, and active ingredients vary by brand. Common ingredients include ketotifen, olopatadine, carboxymethylcellulose and glycerin.
  
• Anti-redness drops: These eye drops usually contain tetrahydrozoline or brimonidine to reduce the swelling of the blood vessels in your eye. They're designed to be used only sparingly.
• Antibiotic drops: These prescription eye drops treat infections such as pink eye or corneal ulcers caused by Pseudomonas aeruginosa. Common drugs include gentamicin sulfate and ciprofloxacin.
  
• Steroid drops: Steroid eye drops are prescribed to reduce symptoms of inflammation like swelling or redness -- for example, after eye surgery.
• Drops for treating certain health conditions: Eye doctors may prescribe various other types of eye drops to treat a range of conditions, like myopia and glaucoma.  

Consult with your doctor

One way to avoid problems with recalled over-the-counter brands is to go to a professional, rather than picking out eye drops yourself. In fact, you should always check with your eye doctor about the right type to buy and how to use them safely.

"People don't always pay attention to what they're buying or why they're buying it," said Dr. Ronald Benner, an optometrist at Southern Montana Optometric Center who has been practicing for more than 30 years. "We strongly recommend that all patients consult with their local optometrist to make sure that they're using the right drop for the right reasons."

Double-check the brand

With so many products being recalled (even some from major brands), the easiest way to stay up-to-date on whether your particular eye product is safe is to Google the specific product name and see if it's been listed in any FDA or CDC warnings, or has been recalled. Take a minute to do this before you put it in your eyes in case anything has changed since you initially bought it.

"Ophthalmic drug products potentially pose a heightened risk of harm to users because drugs applied to the eyes bypass some of the body's natural defenses," the FDA wrote in its Oct. 27 press release. This makes it especially important to avoid products that might not be completely sterile or use safe ingredients. 

Identify the cause of the eye concerns

Because there are so many different eye issues, finding the underlying problem is essential for choosing the right treatment. Benner notes that many patients choose drops that only provide temporary relief without addressing the underlying cause. This can lead to endless reliance on drops or even make problems worse.

Dry eyes, for instance, have many potential causes. They may be a result of allergies, or your time in front of a computer might be a factor. Or you might not naturally produce enough tears. Treatment for each of these causes would be quite different.

"Get the actual help to solve the problem and don't just treat a symptom," said Benner. 

Read more: 12 Best Foods for Eye Health

Consider preservative vs. preservative-free options

Most medications, including eye drops, include preservatives to help keep bugs and bacteria out. As Benner notes, they're meant to protect consumers, but they may not always be the best choice. In some cases, preservatives can irritate the tissues of the eyes.

"The preservative can cause the problems that the drop is supposed to help alleviate," he said. "For many people, using a preservative-free version is much healthier and much more comfortable for the eye."

In his practice, Benner always guides patients who are complaining of sensitivity or had recent surgeries to use eye drops that don't contain preservatives. Often, people who use eye drops regularly will benefit from avoiding preservatives. Again, Benner stresses that your eye doctor can steer you in the right direction based on your situation. 

Consider allergen-free eye drops for sensitive eyes

Preservatives aren't the only potential irritant in eye drops. Antibiotics, beta-blocking agents, corticosteroids, antioxidants and other ingredients have all been associated with eye irritation in some patients. Before you use any eye drops, it's a good idea to consult your eye doctor and read ingredient labels to note any potential allergens.

Safety precautions for using eye drops

Choosing the right eye drops is only the first step in the process. Once you have the correct product in hand, be sure you know how to put in eye drops so you don't cause any harm to your eyes.

Follow the instructions on the label

Each bottle contains instructions for proper application. These ensure you use the proper dose and that it spreads over the whole surface of your eye. Instructions also include guidance on how often to apply the drops and reactions that indicate you should stop. Never use eye drops without reading these instructions.

Wash your hands properly before each use

Your hands may contain dirt, bacteria or other irritants that could affect your eyes, and there's no way to avoid putting your fingers on your eyelids when applying drops. At best, this might offset the benefits of using eye drops. At worst, it might create new problems. Always wash your hands thoroughly with soap and water before applying eye drops.

Avoid contamination

It's also important to keep the eye drop bottle itself sterile and free from germs, as this could result in cross-contamination between your eyes or with another user. Aside from washing your hands before you apply the drops, avoid touching the dropper to your eyes or touching the tip with your hands. Always put the cap in immediately after use and store the eye drops in a clean, sterile environment.

Be on the lookout for expiration dates

All eye drops have an expiration date, which is printed on the bottle. They're usually good for one to two years unopened, but this period may be shorter for eye drops that don't have preservatives.

Keep in mind that preservatives and other active ingredients begin to break down once you open the bottle. This makes them less effective and increases your chances of infection. Most manufacturers recommend throwing away eye drops after they've been open for 28 days. Single-application vials should be discarded immediately after use. 

Tips for correct application

Even with the correct, clean drops in hand, it's important to know how to put eye drops in properly to maximize their effectiveness and reduce your chances of having a reaction. Here are a few steps you can take to correctly apply most eye drops:

1. Wash your hands.

2. Remove the cap and place it in a clean, dry location.

3. Tilt your head back while pulling down your lower eyelid.

4. Squeeze the proper amount of drops into the sac created by pulling down your lower lid.

5. Release your eyelid and close your eyes for 30 seconds to allow the solution to spread across your eye. 

6. Repeat on your other eye if needed.

When in doubt, be sure to review the instructions on the bottle.

Potential side effects 

Depending on the type of product and any allergies you may have, eye drops can cause a range of side effects. Some of the most common include redness, swelling, itching or soreness. More serious side effects may include prolonged burning, discharge, or even hives, swelling, wheezing, dizziness or vomiting. 

These side effects could be the result of an allergic reaction, or they may be a sign of infection or a foreign body irritating your eye. As Benner notes, the only way to be sure is to contact your eye doctor. 

"If the eye stays red or gets redder, those people should be seen ASAP," he said. "If there's mucus, if there's sharp pain in the eye, if there's discharge out of the eye, patients should be seen right away."

Storage, care and travel tips 

Like any other medication, eye drops must be stored properly to prevent spoilage or the development of bacteria. Be sure to follow the manufacturer's instructions for storage location and temperature to ensure your drops stay effective and safe to use. 

Proper storage can be especially difficult to achieve when traveling. If you know your suitcase will sit in a hot car or airplane luggage compartment, for instance, you may want to keep your eye drops with you or run them to your hotel room sooner rather than later. Always check to ensure the lid is secure and free from any risk of contamination.

Too long; didn't read

Like sunglasses and other eye care products, eye drops are an important tool for maintaining eye health. Whether you get them by prescription or over the counter, it's essential to consult with your eye doctor about the correct product and learn how to put eye drops in safely. Eye drops are generally safe to use, but you should always report side effects to your doctor right away -- and avoid using any products that have been recalled.