The following steps should help you choose the best tear supplement and frequency of use for YOU:

1. Understand what “Dry Eye” means.
   Unfortunately, the term “dry eye” is confusing, because it is often used to mean many different
   things.
   The eye must be kept lubricated, both for the health of the eye and for the optics of the eye, so
   that the eye can see clearly. A deficiency in either tear quantity or tear quality can result in inadequate
   lubrication of the eye. High quantity tear production, as happens in emotional crying or when the eye
   is irritated or very dry, typically does not produce “good quality” lubricating tears.
   There are three basic components of “high quality” lubricating tears: a mucin component, an
   aqueous or watery component, and an oil component. Inadequate quantity or quality of any of these
   three components will disrupt the lubricating effect of the tears and may even create “toxic tears,”
   tears which are irritating and inflammatory to the eye and eyelids.
   All eye doctors are trained in recognizing and managing the different types of “dry eye,” but
   there are some professionals who specialize specifically in treating these problems. Regardless of the
   cause and individualized treatment, nearly all people with a “dry eye” or “tear film” problem benefit
   from some degree of tear supplementation. Which supplement is best for you and when you should
   use it probably is best determined by YOU!

2. Understand what is and what is NOT a tear supplement.
   Tear supplements are supposed to lubricate the eye, nothing else. Over-the-counter drops
   that are advertised to “take the red out” are NOT tear supplements and should generally NOT be
   used without the explicit instruction of an eye doctor. A “red” eye is typically an inflamed or irritated
   eye, and the underlying cause needs to be determined and addressed. Shrinking the blood vessels
   on the surface of the eye will whiten the eye, but this does NOT treat the underlying pathology, and
   frequent, chronic use of such drops can contribute to vision loss.
   With rare exceptions, prescription eye drops are NOT tear supplements. Restasis, most
   appropriate for a very specific type of “dry eye” problem, is a chemotherapy drug, not an eye
   lubricant.
   An EYE RINSE or an EYE WASH is also not the same as a tear supplement and vice versa.
   Tear supplements are engineered to bind to the surface of the eye and are not the best choice to
   rinse away allergens, eye irritants, or even other thicker tear supplements that may have been used
   overnight. An eye rinse or eye wash is typically just saline solution available in bottles that are larger
   and cheaper than tear supplements.
   People who have “posterior lid margin disease blepharitis,” also called “meibomitis,” “lid margin
   sebaceous hyperplasia,” or “ocular rosacea,” are often encouraged to apply warm compresses to
   their eyes to melt or thin the oil component of their natural tears. In the first few weeks of starting
   treatment, eye rinses or eye washes may be useful to rinse out the thick oil of their own tears
   BEFORE using a tear supplement.

3. Understand what is in a tear supplement.
   There are four important characteristics of modern tear supplements that should be considered
   when choosing a supplement: the preservative, the type of gel, the amount of gel, and the presence
   of other “protective” factors.

• Preservatives
  Preservatives prevent bacterial contamination once a supplement bottle has been opened.
  Reaction to a preservative is the most common reason why someone may have an allergy to or
  experience irritation from a supplement. Drops without preservatives are available, but preservativefree drops tend to be the more expensive and usually come in individual dispensing units, which may
  or may not be desirable. Common preservatives include:

Benzalkonium Choloride
Biguanide
Chlorobutanol
Oxyborate compounds
Polyhexamethylene
Polyquad
Polyquaternium
Purite
Sodium Chlorite
Sodium Silver Chloride
Sodium Perborate
Sorbic Acid

• Gel Type
  The gel is the most important component of a tear supplement, because it is what allows the
  supplement to stay on the eye longer than just saline. Some people may find a particular gel is more
  comfortable for them than others. While other people may find that mixing supplements containing
  different gels provides the most benefit. Listed below are some of the more common tear
  supplements organized by the gel they contain. Note that some drops contain multiple gels already.
  Those marked with * are ones our patients seem to like the most.

Carboxy Methyl Cellulose (CMC) Based
Refresh Liquigel
Refresh Optive*
Refresh Tears
Thera Tears*

Glycerin Based
Advanced Eye Relief
Moisture Eyes
Refresh Optive*
Similasan Dry Eye*
Soothe*
Tears Natural Forte

Hydroxypropyl Methylcellulose (HPMC) Based
Bion Tears*
Genteal
Genteal Gel*
Genteal Mild
Tears Natural II
Tears Natural Free
Tears Natural Forte

Oil Based
Retain MGD* Refresh Endura Soothe XP Emollient*

Polyethylene Glycol Based
Blink Tears Systane Systane Ultra

Polyvinyl Alcohol Based
Akwa Tears Hypotears Tears Tears Again

• Gel Concentration / Percentage
  The more gel present in the drop, the higher the percentage in the solution and the longer the
  supplement coats and protects the eye. But higher gel percentages increase temporary vision
  blurring. Mixing supplements of different gel percentages by sequentially placing different
  supplements in the eyes is an option, allowing the creation of unique gel percentages. For example, a
  0.2% gel may be added after a 0.4% gel to create a situation that approximates 0.3% gel supplement,
  which will last longer than the 0.2% drop, but not blur the vision as much as the 0.4% lubricant.
  Typically, a thinner drop might be chosen for use during the day, whereas a very thick drop or
  ointment could provide more benefit at night while sleeping.
  Some of the thickest gels/ointments best for nighttime use include:
  

Genteal Gel
Lacri-lube ointment
Refresh PM ointment
Tears Again Night Gel
Tears Naturale PM
Duralube ointment
Puralube ointment
Even Vaseline may be used in people who have no reaction to petroleum jelly and do not mind
the arduous eye rinsing in the morning. Vaseline comes in a tube. Placing this in a mug or glass of
hot tap water for 20 seconds will typically make it quite runny.

• Other Protective Factors
  Some supplements have additional ingredients which the manufacturers believe confer greater
  comfort and supplement stability. The comfort benefits of these added factors are mostly personal and not necessarily substantiated by study but are worth considering. Examples include:

Akwa Tears (hypo-osmolar salts)
Blink Tears (hyaluronic acid)
Optive (hyper-osmolar salts)
Sytane Ultra (HP-guar)
Retaine MGD (poloxamer 188)

4. Choose a Tear Supplement.
   – One of the supplements marked with an * above may be a reasonable first choice.
   – If the drop causes itching or burning, the preservative is the most likely culprit and choosing
   a supplement containing a different preservative or no preservative at all (preservative-free)
   is a reasonable next step.
   – If the tear supplement feels gritty, slimy, or leaves a “sticky residue,” choose a supplement
   with a different gel.
   – If the tear supplement doesn’t last very long, requiring very frequent application, then a
   drop with a higher percentage of gel should be tried.
   – If the drop blurs the vision too much, then it is too thick, and consider a supplement with a
   lower percentage of gel or mix in a thinner gel. The higher the gel concentration, the longer
   the supplement lasts, but the more likely it is to cause blurry vision.

5. Determine When and How Often to Use Tear Supplements.

• Bedtime If the eyes are not dry or irritated in the middle of the night or upon awakening, a supplement at bedtime is probably not necessary. An eyedrop before going to bed likely has little use, as it will not last very long. If a night-time supplement is needed, a thick gel is probably warranted. Avoiding sleeping directly under a ceiling fan or heating vent may be helpful.
• Daytime
  Following a regular, timed schedule of supplement use is not as useful as situation-based
  application. For example, applying makeup, reading, working at the computer, watching TV or
  a movie, and driving require visual concentration and, in most people, decrease the natural
  blink rate by at least 3-fold. Since a blink acts as a “reverse windshield wiper” smearing tears
  across the eye, decreased blinking means decreased eye lubrication, and using tear
  supplements before and during such activities is often helpful.
  Any factor that increases natural tear evaporation (i.e. a brisk wind, cold weather, indoor
  heating, diminished blinking) will require more frequent tear supplementation.
  Once the eyes have dried out, tear supplementation is less effective at providing comfort. So,
  identifying drying factors and using the tear supplements BEFORE exposure to such drying
  influences is more effective in keeping the eyes safe and comfortable.
  Eyes are not smart. They can’t tell the difference between a dry eye / tear film problem and a
  stick or eyelash in the eye. The response to all eye irritation is often to make copious amounts
  of “water tears.” These are “washing tears,” not “lubricating tears.” Thus, excessive tearing
  may be due to the eyes being “dry.” Learning what things make your eyes water may be the
  same as learning what things make your eyes dry and using tear supplements BEFORE
  entering such situations may diminish excess tearing. Common “dry eye” symptoms include
  burning, gritty feeling, eyelid heaviness, and eye fatigue, although these may be absent, and
  the only clue might be excessive tearing.
  To avoid prolonged blurring of both eyes simultaneously, supplements of different
  thickness/percentage may be used in the two eyes. For example, a 0.2% solution can be used
  in one eye while a 0.3% solution is used in the other and then reversed a couple of hours later.
  Or the same supplement may be applied to both eyes at different times. Finally, supplements
  of different gel concentrations may be combined by rapid sequential instillation to create
  unique gel concentrations.

Remember, tear supplements may be used as often as desired, and for some people, slow, frequent
blinking may be just as effective as the use of tear supplements.
An excellent reference for determining the composition of many additional tear supplements not
covered here is the following link: http://www.dryeyezone.com/encyclopedia/lubricants.html