Used in the same sentence, the words “red” and “eyes” don’t usually signal good news.

But a new University College London study suggests that just three minutes of exposure to deep red light once a week can significantly boost declining eyesight.

That’s only if the exposure comes during the morning, however.

Testing a group of 20 adults with normal eyesight, the researchers exposed participants to three minutes of 670-nanometer [nan-oh-meter] red light between 8 and 9 a.m. Their vision was tested three hours after exposure and half of the participants were tested a week later.

They found an average 17% improvement in the study participants’ color contrast vision following the morning red-light exposure, and those effects lasted at least one week. But when they tried the same test in the afternoon, they found no improvement.

As most anyone who’s lasted four decades on this planet knows, most of us begin to see declines in our sight around age 40. That’s about the time we start wanting to know who shrank the writing on soup can labels.

That’s because retinal cells begin to age, meaning they can’t produce energy as well as they used to. The retina ages faster than other organs.

The researchers have previously tested deep red-light exposure on mice, bumblebees and fruit flies, finding significant improvements in the retina’s photoreceptors when their eyes were exposed to the long-wavelength light.

Despite the recent study’s small size, its findings mean inexpensive devices may soon find their way to consumers that could help millions of vision-impaired people.

Imagine: A quick once-a-week recharge of our retina cells as we make our morning coffee and we could leave our cheater glasses at home.