Dry eye relief in San Antonio, Texas

In San Antonio, dry eyes usually come from heat and the air conditioning it demands, not from dry outdoor air. The airport averages about 122 days a year at 90°F or hotter, and August afternoons settle near 50 percent humidity. Aim vents away from your face, blink fully during screen work, carry sunglasses, and use a lubricating drop only as its label directs. See an eye doctor for pain or vision changes.

San Antonio’s climate by the numbers

San Antonio sits where the Hill Country meets the South Texas brush country, and its weather borrows from both. NOAA’s 1991 to 2020 normals for San Antonio International Airport give a picture of a long, hot warm season and a mild winter:

• About 122 days a year reach 90°F or more, and close to 18 reach 100°F.
• August is the hottest month, with a normal high of 96.0°F and a low near 75°F.
• Normal precipitation is 32.38 inches a year, with May (4.40 inches) and September (3.88) the wettest months.
• Winter is gentle. January’s normal high is 63.3°F and the airport averages just 14 nights a year at freezing or below.
• The station sits at about 790 feet, on gently rolling ground north of downtown.

Is San Antonio humid or dry?

Somewhere in between, and it depends on the hour. NOAA’s relative humidity table gives the city a morning average of 83 percent across the year and an afternoon average of 55. In August, mornings start at 86 percent and afternoons fall to about 50. That swing is why a morning run along the Mission Reach can feel muggy and a 4 p.m. walk from a parking garage can feel like a hair dryer.

Outdoor humidity in the 50s isn’t especially hard on eyes by itself. The bigger factor is how much of the day San Antonians spend in cooled air.

Air conditioning for most of the year

With normal highs above 80°F from April through October, air conditioning in San Antonio runs for most of the year. Cooling air wrings water out of it, and the fans that move it blow straight across your face if a vent is pointed the wrong way. Office workers at a desk under a ceiling diffuser, drivers with the dash vents aimed up, and people sleeping under a ceiling fan all get a steady breeze that speeds evaporation from the tear film.

• In the car, angle dash vents toward your chest or the windshield instead of your eyes.
• At work, ask whether a diffuser over your desk can be redirected, or move the monitor so you aren’t facing the airflow.
• At night, turn the ceiling fan down or off once the room has cooled.
• Keep a glass of water at your desk; you’re more likely to take breaks, and those are blink breaks too.

Sun, glare and outdoor plans

San Antonio’s outdoor life runs on shade: the River Walk’s cypress trees, the missions’ stone courtyards, and Hill Country swimming holes on summer weekends. Glare off water and pale limestone makes people squint, and squinting tends to cut blinks short. Good sunglasses with side coverage help with glare and with the wind on a boat or a bike ride along the Salado Creek Greenway. A brimmed hat does more than you’d expect.

Fiesta in April and summer weekend trips to the coast can mean long days outside. Plan breaks indoors and keep your drops in a bag rather than a hot car. The label sets a storage range, and a parked car in August blows through it: Store between 15° to 30°C (59° to 86°F).

Winter fronts and heated rooms

A San Antonio winter is mostly mild, but cold fronts can drop temperatures sharply for a few days at a time. When the heater kicks on, indoor air dries out quickly. January afternoons outdoors average 57 percent humidity, so the outside air isn’t the issue; a forced-air system running hard is. The airport’s 14 or so freezing nights are when it’s most noticeable. Our guide to winter heating and dry eyes has room-by-room ideas.

What Quell is and what the label says

Quell is a preservative-free lubricating eye drop designed to reinforce the tear film’s oil layer to help reduce moisture loss. The Drug Facts Uses read: For use as a protectant against further irritation or to relieve dryness of the eye. The directions read: Apply 1 drop 3 times per day in each eye. One handling rule: Do not touch tip of bottle to any surface to avoid contamination.

There’s one caution to check first: Caution should be used in those with egg or bird allergies — For use in the eyes only. The bottle is .33 fl oz (10 mL). The label doesn’t give directions for contact lenses, children or combining it with other eye drops, so ask an eye doctor or pharmacist before using it in any of those situations. You can read every line on the Drug Facts page.

Ordering to San Antonio

Quell ships from Brentwood, Tennessee, to San Antonio, New Braunfels, Boerne and anywhere else in Texas. Check out as a guest; shipping is $10.00, or free on 3 or more bottles. A tracking email arrives once it ships, but no delivery date is promised, so give yourself some room. If a bottle stays unopened, it’s refundable within 30 days of delivery and you keep it. See the San Antonio page, the Texas page, or the home page.

When to see an eye doctor

A lubricating drop is for ordinary dryness. If yours keeps coming back no matter what you change, an eye doctor can work out the cause and what to do about it. The label says when to stop: Stop use and ask a doctor if you feel eye pain or changes in your vision, if irritation or redness continues, or if the condition worsens or persists for 72 hours.

Before the appointment, our dry eye self-check can help you put words to your symptoms; it’s not a diagnosis. Sudden pain or a change in vision means calling a doctor that day.