Overview
The eyes are part of the visual system and work with the brain, nerves, and eye muscles. Light enters through the front of the eye, is focused by the cornea and lens, and is detected by the retina at the back of the eye. The optic nerve carries this information to the brain, which turns it into the images you see. Healthy eyes are important for reading, driving, movement, communication, and independence.
Key Symptoms
Eye symptoms can include blurred vision, trouble seeing at night, double vision, eye pain, redness, itching, tearing, dryness, sensitivity to light, flashes, floaters, or partial loss of vision. Some people also notice headaches, eye strain, or difficulty focusing. Symptoms may affect one eye or both eyes and can come on gradually or suddenly. Sudden vision changes should be taken seriously.
Causes and Risk Factors
Eye problems can happen because of aging, genetics, infection, injury, long-term health conditions such as diabetes or high blood pressure, and environmental exposures such as UV light, smoke, dust, or chemicals. Screen use may contribute to eye strain and dryness in some people. Contact lens misuse can raise the risk of infection. Some medicines and autoimmune conditions can also affect the eyes.
Who Is Affected
Everyone can have eye problems, from newborns to older adults. Children may have vision issues that affect learning and development, while older adults are more likely to develop cataracts, glaucoma, and age-related retinal disease. People with diabetes, a family history of eye disease, past eye injuries, or limited access to eye care may have higher risk. Eye disease can occur in any country and setting.
Prevention
Not all eye conditions can be prevented, but some risks can be lowered. Wear protective eyewear for sports, tools, chemicals, and dusty work, and use sunglasses that block UV rays when outdoors. Wash hands before touching your eyes or contact lenses, follow lens care instructions carefully, and avoid sharing eye makeup or drops. Regular vision and eye checks can help find problems early.
Diagnosis and Tests
Eye problems are evaluated with a medical history and an eye examination. Tests may include visual acuity, refraction, eye pressure measurement, pupil checks, slit-lamp examination, retinal examination, and imaging when needed. Children may be screened for vision problems even if they do not report symptoms. People with long-term conditions such as diabetes may need regular eye exams because damage can happen before symptoms appear.
Treatment Categories
Treatment depends on the cause and may include glasses or contact lenses, lubricating drops, medicines, procedures, laser treatment, or surgery. Infections, inflammation, injuries, and chronic eye diseases each need different approaches. Early treatment can help protect vision in some conditions. Follow-up care is often important to monitor changes over time.
Diet and Lifestyle
General health habits support eye health. Managing conditions such as diabetes and high blood pressure, not smoking, getting enough sleep, and taking breaks during close-up work may help reduce strain and protect vision. A balanced diet that includes fruits, vegetables, and other nutrient-rich foods supports overall eye function. Good lighting for reading and work can also make the eyes more comfortable.
When to Seek Medical Care
Arrange medical care if you have ongoing blurry vision, eye discomfort, redness that does not improve, repeated headaches with visual symptoms, new floaters, or trouble seeing at school, work, or while driving. Eye care is also important after an eye injury, chemical exposure, or if a child seems to squint, sit very close to screens, or has one eye that wanders. Regular eye exams are important even when symptoms are mild or absent.
When It May Be an Emergency
Get urgent medical help right away for sudden vision loss, severe eye pain, chemical splashes, an object stuck in the eye, major eye injury, sudden flashes with many new floaters, or a dark curtain over part of your vision. Also seek urgent care for eye symptoms with severe headache, nausea, weakness, confusion, or trouble speaking. These symptoms can signal a serious eye problem or another medical emergency.