Keratoconus

Keratoconus is a progressive eye disease where the normally round, dome-shaped cornea thins and bulges outward into a cone shape. This irregular shape distorts light as it enters the eye, causing blurred and distorted vision that cannot be fully corrected with standard glasses.

Disease

Symptoms

Vision becomes progressively blurry and distorted at all distances. You may see "ghost" images, experience increased light sensitivity and glare, and find that your glasses prescription changes frequently. It often starts in the teens or early 20s. Risk factors include a family history, vigorous eye rubbing, and certain connective tissue disorders.

Diagnosis

Diagnosis involves corneal topography and tomography, a painless imaging test that creates a detailed 3D map of the cornea's surface curvature. This map reveals the characteristic cone-shaped steepening.

Treatments

In early stages, specialty contact lenses (rigid gas permeable, scleral lenses) are the primary treatment to create a smooth visual surface. A procedure called corneal cross-linking uses UV light and eyedrops to stiffen the cornea, which can stop the progression. In advanced cases where vision is very poor, a corneal transplant may be necessary.

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

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

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.