As Americans live longer, ordinary routines may be affecting their eye health sooner than expected. Dr. Douglas Lazzaro, professor of ophthalmology at NYU Langone Health, warned that sun exposure, dim lighting, poor diet, dehydration, inadequate sleep, eye rubbing and delayed exams can quietly threaten vision.

The risks become especially important as people age. Glaucoma damages the optic nerve, while cataracts cloud the eye’s lens, potentially blocking light and blurring vision.

Genetics and aging remain major forces behind many eye diseases, but Lazzaro told Fox News Digital that avoiding common mistakes may help protect sight and slow the progression of certain conditions. One major concern is failing to shield the eyes from sunlight.

Although sunlight exposure can benefit metabolic health and longevity, extended ultraviolet exposure may contribute to macular degeneration and worsening cataracts. Lazzaro recommends wearing sunglasses during bright, sunny conditions to protect structures including the lens and retina.

In his own practice, Lazzaro has seen cataracts appearing five to 10 years earlier than they did three decades ago. He believes that shift may be connected to ultraviolet light exposure, making consistent protection an important consideration.

Poor lighting presents another challenge, particularly for older adults. Reading under inadequate light can increase strain, make focusing more difficult and create problems as the eyes become less able to adjust to darker environments.

Nutrition may also influence vision because poor diets can contribute to diabetes and cardiovascular disease, both of which can affect the eyes. "Diet is important," Lazzaro said. "There's certainly a lot of known data about poor diets [contributing] to poor cardiovascular health, and that same thing can apply with the eye."

High cholesterol and high blood pressure may worsen diabetic eye disease, even when patients do not realize those conditions are affecting their sight. Researchers are also examining whether gut health influences retinal health, although Lazzaro said that connection is still emerging.

Dry eye becomes increasingly common with age and can leave the eyes red, itchy and irritated. The condition occurs when insufficient tear production and oil secretion prevent the eyes from remaining properly lubricated, and dehydration may make the discomfort worse.

Staying hydrated helps keep the cornea properly moisturized, according to Lazzaro. "We always tell our patients, particularly in the summer, if they're going out on a hot day … make sure to hydrate, because not only will it dry out the body … but it can dry out your corneas."

Inadequate sleep can create another potential danger. Lazzaro said there is "good evidence" that patients who sleep poorly, particularly those with sleep apnea, may experience increased pressure inside the eyes.

People with sleep apnea also appear to have higher rates of glaucoma and certain vascular eye conditions, similar to their increased cardiovascular risk. Lazzaro said poor sleepers may experience changes in their circulation during the night that can affect eye health.

Eye rubbing is another habit Lazzaro strongly advises patients to avoid. It is considered a risk factor for keratoconus, a progressive disease in which the cornea begins to dome and bulge outward into a cone shape.

Experts differ on whether rubbing can directly cause keratoconus, but patients with the condition frequently rub their eyes. Repeated rubbing can potentially alter the cornea’s shape, providing another reason to stop the habit.

Skipping comprehensive eye exams can allow serious problems to remain hidden. Glaucoma is often called the silent thief of sight because it may develop without symptoms, and an ophthalmologist’s examination may be the only way to detect it before significant vision loss occurs.

Lazzaro recommends annual eye exams instead of waiting for noticeable changes. Presbyopia, the gradual loss of the ability to focus on nearby objects, commonly appears during middle age and often causes people between 40 and 50 to seek reading glasses.

Annual appointments should also include checks for skin cancer and eyelid tumors, which become more frequent with age. Lazzaro said sun exposure may contribute to eyelid cancers as well as cataracts and macular degeneration, while most eyelid cancers can be removed locally without a major problem when found early.