Eye damage does not always cause pain or blurred vision from the outset. Some conditions progress slowly, only becoming apparent when vision has significantly deteriorated. According to the World Health Organization (WHO), the following eye diseases can lead to severe vision impairment, even permanent blindness, if not treated promptly.

Glaucoma

Glaucoma is a group of diseases that damage the optic nerve, often linked to the gradual loss of retinal nerve cells. The condition can progress silently for many years.

According to the National Eye Institute (NEI) in the US, early-stage glaucoma typically presents no symptoms. Patients may gradually lose peripheral vision while maintaining clear central vision, making early detection difficult. As the disease advances, vision can be severely affected, ultimately leading to blindness if left untreated.

A characteristic that makes glaucoma easily overlooked is that patients often retain good vision in the initial stages. Therefore, in addition to diagnostic methods like eye chart examinations, doctors may need to measure intraocular pressure, assess the optic nerve, evaluate visual fields, and perform optical coherence tomography (OCT) of the retina, depending on the individual case.

Age-related macular degeneration can silently affect central vision, making reading difficult as the disease progresses. Illustration: AI

Diabetic Retinopathy

Diabetic retinopathy occurs when prolonged high blood sugar levels damage blood vessels in the retina. This is a significant eye complication of diabetes.

Notably, the early stage of the disease often presents no symptoms. As the damage progresses, patients may experience blurred vision, floaters, or dark spots. Severe cases can lead to vitreous hemorrhage, macular edema, tractional retinal detachment, or vision loss.

The NEI recommends that individuals with diabetes undergo a comprehensive eye examination at least once a year. Managing blood sugar and addressing risk factors also helps reduce the risk of eye complications.

Age-Related Macular Degeneration

Age-related macular degeneration (AMD) affects the macula, the central part of the retina responsible for central vision and the ability to see fine details.

Early-stage AMD often causes no symptoms, and some individuals in the intermediate stage may not yet notice any changes in their vision. The disease can progress slowly, meaning patients might only detect it once their central vision has declined.

As AMD progresses, patients may experience blurred central images, straight lines appearing wavy or distorted, blank spots in their vision, and difficulty reading or recognizing faces. Regular eye exams can help detect macular changes before patients clearly notice symptoms.

Cataracts

Cataracts typically develop gradually as the eye's natural lens becomes cloudy, making it difficult for light to pass through and affecting the images transmitted to the retina.

In the initial stages, patients may not notice any symptoms. As the clouding worsens, vision can become blurry or appear hazy, colors may seem faded, night vision might be difficult, and individuals may experience light sensitivity or see halos around lights.

If left untreated as they progress, cataracts can cause significant vision impairment. However, unlike optic nerve damage from glaucoma, vision loss due to cataracts can often be improved with cataract surgery when indicated.

Hypertensive Retinopathy

Prolonged high blood pressure can damage the small blood vessels in the retina, leading to hypertensive retinopathy. These changes may occur without patients noticing clear symptoms in the early stages. The condition is diagnosed through a fundus examination, with doctors also considering the degree and duration of hypertension and any damage to other organs.

In cases of severe damage, patients may experience reduced vision. Hypertension also increases the risk of vascular events in the retina, which can further impact vision. Blood pressure control is crucial in reducing the risk of eye damage and vascular complications.

Bao Bao (Compiled)