Refractive Error

Refractive error means that your eye does not focus light ideally onto the retina, resulting in a blurred image on the retina. This condition is not a disease, but a common problem with light focusing. Its main types include myopia (nearsightedness: nearby objects are clear while distant objects appear blurry), hyperopia (farsightedness: distance vision may be clearer than near vision), and astigmatism (vision is blurry at all distances due to an irregularly shaped cornea).

Disease

Symptoms

A refractive error means the shape of your eye doesn't bend light perfectly, causing a blurry image on your retina. It's not a disease, but a common focusing problem. The main types are myopia (nearsightedness: close things are clear, far things are blurry), hyperopia (farsightedness: distance vision may be clearer than near), and astigmatism (vision is blurred or distorted at all distances due to an irregularly shaped cornea).

Diagnosis

The main symptom is blurry vision for distance, near, or both. You may also experience eyestrain, headaches, or squinting. Risk factors include family history and age-related changes (like presbyopia, the normal loss of near-focusing ability after age 40).

Treatments

Refractive errors are easily corrected with eyeglasses or contact lenses. For a permanent correction, laser vision correction surgery (like PRK, trans PRK, femto LASIK, SMILE) or implantable lenses are options for suitable candidates.

More to read

Disease

Cataract

A cataract is a clouding of the eye's natural, clear lens. Think of it as a clear window that slowly becomes frosted. This clouding scatters light, preventing a sharp image from reaching the retina. It is most commonly related to aging. However, some forms of congenital cataract are seen in children.

Disease

Night Blindness

Night blindness is a symptom, not a disease. It means your eyes have trouble adapting to low light. This is often due to a problem with the rod cells in your retina, which are responsible for night and peripheral vision.

Disease

Color Blindness

Most color blindness is not complete blindness to color, but a difficulty telling certain colors apart. It is usually an inherited condition (more common in males) present from birth. It happens when certain light-sensitive cone cells in your retina don't work properly. The most common type is trouble distinguishing reds from greens.

Disease

Retinopathy of Prematurity

ROP is a disease that affects premature infants. In the womb, the retinal blood vessels grow late in pregnancy. When a baby is born very early, this normal growth is interrupted. After birth, abnormal, fragile blood vessels may begin to grow in the retina. These vessels can leak and scar, potentially pulling the retina off (detachment).

Disease

Retinal Detachment

A retinal detachment is a medical emergency. It occurs when the retina peels away from the back wall of the eye, like wallpaper bubbling off a wall. When detached, the retina cannot function, leading to vision loss.

Disease

Retinal Hemorrhage

A retinal hemorrhage means there is bleeding inside the layers of your retina. Think of it as a bruise on the light-sensitive film of your eye. It is a sign of an underlying problem, not a disease itself.