Spring is a time of renewal. Songbirds sing their loudest and most eloquent songs to mark and own their territory and to attract a mate. Flowers emerge through the cool, damp soil from bulbs that have slowly prepared from fall to present a kaleidoscope of colors, which brighten our days. Grasses awake from their dormancy to claim their space in the yard. Trees sprout new growth to repair the traumas from winter storms.

Trees are spring's first large scale producers of buds, flowers and pollens. Grasses, molds and weeds follow as the seasons advance. It's the pollens that blur the vision of our contact lens-wearing patients.

Pollens affect contact lens wearers in multiple ways. Pollens are both physical and immunologic irritants, affecting roughly 10 percent to 20 percent of the population, with even greater percentages in the warmer and humid climates.

Your environment dictates allergen concentrations. Not only humidity and temperature affect pollen counts, so does atmospheric carbon dioxide. As carbon dioxide concentrations increase, so do the number of pollens and other allergens in our environment.

A Harvard Medical School study found that ragweed grown in an atmosphere with double the current carbon dioxide levels produced 61 percent more pollen. Regrettably, atmospheric carbon dioxide levels are expected to double over the next 50 years.

The greatest tree-generated physical irritant is the bi-lobed, vesiculated pine pollen, which feels like aerated sand to our lens-wearing patients. Allergic rhinitis with associated allergic conjunctivitis is the main immunologic consequence to seasonal tree pollens. Contact lens wear can be challenging in this environment.

Here are some tips you can pass on to your contact lens wearers to keep them more comfortable throughout the spring.

Advise patients to wear goggles or close-fitting sunglasses when outside and to keep home and automobile windows closed.

High efficiency air filters and electrostatic air cleaners can remove pollen and dust, improving air quality in central air conditioning systems. Replace disposable filters monthly during heavy pollen seasons.

Frequent use of low-viscosity, preservative-free artificial tears will help to dilute and rinse out tear film irritants. In-eye contact lens cleaners such as Blink-n-Clean (AMO) or Clerz Plus (Alcon) can also be helpful.

Systemic antihistamines can help alleviate allergic symptoms, but are associated with ocular dryness. Advise patients to use topical decongestants sparingly to avoid vascular rebound. Mast cell stabilizers are helpful if used before symptoms occur. Combination drops (Elestat [Allergan], Optivar [MedPoint Pharmaceuticals], Patanol [Alcon], Zaditor [Novartis Ophthalmics]) seem to offer the greatest relief of symptoms by combining the immediate antihistaminic relief with the prolonged effect of mast cell stabilizers.

Tell patients to ignore the no rub product labeling and to rub and rinse upon removal to decrease accumulated debris from the lens surfaces. If you suspect a solution-related hypersensitivity or toxicity, change to peroxide disinfection to eliminate possible preser-vative sensitivities.

Washing face and hands often with cold water can be very effective in relieving symptoms. Cold compresses help relieve ocular itching (try putting ice cubes in a wet wash cloth). Advise patients who have severe signs or symptoms to avoid wearing lenses.