Dry eyes in Reno, Nevada

Reno’s air is dry most of the year because the city sits in the rain shadow of the Sierra Nevada. NOAA’s 1991–2020 normals give Reno-Tahoe International Airport 7.35 inches of precipitation a year, and summer afternoons there average 18 percent relative humidity. Dry, moving air pulls moisture off the eye faster, so many people notice it. Quell is used the same way there as anywhere: Apply 1 drop 3 times per day in each eye.

Why Reno is so dry: the Sierra rain shadow

The National Weather Service office in Reno has written about this directly. In a 2007 technical paper on forecasting storms east of the mountains, two of its forecasters called the Sierra Nevada an excellent example of the rain shadow effect. The windward slopes in California average 50 to 75 inches of precipitation a year. The Reno metro area, in the lee of the range, averages 7 to 14 inches.

The mechanism is simple enough. Pacific storms are forced up the west side of the range and drop most of their water there. By the time the air sinks into the Truckee Meadows, much of it has been wrung out. The same NWS paper describes mountain waves bringing strong downslope winds into the valleys east of the crest when storms cross. Low humidity plus wind is the pairing the site’s guide to dry air, wind and altitude describes: moving air carries water off the surface of the eye faster than still air does.

What NOAA’s numbers show for Reno

• Precipitation: NOAA’s 1991–2020 climate normals for the airport give 7.35 inches a year. Of that, 3.38 inches falls from December through February, and only 0.85 inch across June, July and August combined.
• Wet days: the same normals count about 50 days a year with at least a hundredth of an inch of precipitation. The other 300-plus days have none worth measuring.
• Humidity: NOAA’s Comparative Climatic Data tables, built from the airport’s record from 1949 to 2018, list average afternoon relative humidity of 18 percent in July and in August, and 31 percent across the whole year. Mornings run higher, at 63 percent on the annual average.
• Clear skies: the same tables count an average of 158 clear days a year.
• Elevation: NOAA lists the airport weather station at 1,344 meters, about 4,410 feet above sea level.
• Summer heat: the 1991–2020 normals give an average June-to-August high of 90.2°F.

Those are airport readings. Homes up in the foothills, out in Sparks or north in the valleys toward the state line will run a little different, but the broad pattern holds across the area: high desert, low rainfall, big swings between morning and afternoon humidity.

Reno’s seasons and your eyes

Winter is the wettest season on paper, and it’s also when furnaces run in nearly every house. NOAA’s normals put the average December-to-February low at 26.9°F, so the heat stays on for months. Forced-air heat dries indoor air on top of a climate that is already dry, which is why some people in Reno notice their eyes more in a warm living room in January than out on a cold sidewalk.

Summer brings the lowest humidity of the year. With afternoon readings around 18 percent and highs near 90, most people drive with the air conditioning on and spend the hot part of the day in cooled offices, stores and casinos. Air conditioning dries a room too. Put a phone or a monitor in front of you and the picture gets worse, since people blink less while they read a screen, and blinking is what spreads the tear film back across the eye.

Wind can show up in any season. It comes with the storms that cross the Sierra, which the NWS paper ties to strong gusts east of the crest. On a gusty afternoon along the Truckee River or on a foothill trail, wraparound sunglasses block some of it before it reaches your eyes.

Day trips up to Lake Tahoe

Plenty of Reno weekends end up at the lake or on the ski slopes, which means more altitude, more sun off the water or snow, and a car parked for hours. A bottle in the glove box can spend that time outside the label’s range, hot in July and cold in January. Quell’s storage line reads: Store between 15° to 30°C (59° to 86°F). Carry the bottle in the bag you take with you. The guide to eye drops in a hot car explains why the car is the problem.

Using Quell in a dry climate

The directions don’t change with the weather. The label says: Apply 1 drop 3 times per day in each eye. It doesn’t say to add drops in a dry place, and the guide to using more than three drops a day explains why that question goes to a doctor or pharmacist rather than to a shop.

Quell is designed to reinforce the tear film’s oil layer to help reduce moisture loss. That oily outer layer sits over the watery middle layer and slows evaporation, which is exactly what Reno’s air works against. The label’s Uses line reads: For use as a protectant against further irritation or to relieve dryness of the eye.

Dust and wind make two label rules worth repeating. Wash your hands before you open the bottle, and keep the tip off everything: Do not touch tip of bottle to any surface to avoid contamination. Look at the liquid before each dose, too, because the Do not use line reads: If this product changes color. The eye drops have a naturally milky-brown appearance. This is normal and does not indicate a problem with the product.

When to see a doctor in Reno

Dry weather explains a lot of mild discomfort, but not all of it. 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. An optometrist or ophthalmologist in Washoe County can examine what a drop can’t. If you’d like a list of questions to bring, the dry eye self-check takes a few minutes and is not a diagnosis.

Ordering Quell to a Reno address

Quell ships from Brentwood, Tennessee to Reno, Sparks and the rest of Nevada. Shipping is $10.00 per order, and it’s free on 3 or more bottles. The Reno page and the Nevada page cover local ordering, and checkout works as a guest. In July and August, bring the package in soon after it lands on the step rather than leaving it in the afternoon sun.