What causes cataracts?

What causes cataracts?

What causes cataracts?

What causes cataracts to form?

The most commonly associated causes of cataracts are aging (known as age-related cataracts) and sunlight exposure (resulting in changes to eye tissues). It is normal for vision changes to develop as we age (i.e. lenses become less flexible with reduced transparency and thicken which can promote clumping), but it is not necessarily a given that age-related changes will lead to the formation of cataracts.

Other common underlying causes of cataracts are:

  • Ultraviolet (UV) radiation exposure – sunlight, sunlamps or tanning booths
  • Long-term use of certain medications, such as steroids (oral corticosteroids) and diuretics
  • Certain conditions, such as diabetes (i.e. blood sugar changes, especially when above the safe range, can lead to vision changes, such as blurriness in the eye/s.).
  • Diseases of the skin and mucous membranes, such as atopic dermatitis, or other health conditions such as hypothyroidism can result in early onset development of cataracts.
  • Eye diseases – retinitis, glaucoma, retinal detachment, long-term uveitis, iritisor uveitis or retinitis pigmentosa may cause or accelerate the development of cataracts.
  • An overproduction of oxidants in the body (i.e. oxygen molecules which chemically alter)
  • Smoking habits and air pollution exposure increase the risk of cataract development.
  • Radiation therapy or frequent head X-rays (exposure to ionising radiation or infrared radiation).
  • Trauma (i.e. penetrating or blunt injury to the eye).
  • Following a vitrectomy procedure whereby vitreous gel is removed from the eye (increasing risk of developing cataracts).

Cataracts may also be present at birth (congenital), meaning that some children are born with this type of visual impairment (in one or both eyes). Congenital cataracts may be stationary (do not gradually worsen) or progressive (grow larger over time).

Some congenital infections (an infection which may be passed from mother to child during pregnancy and/or birth) can also lead to the development of cataracts in a young baby.

Some of these may include:

  • Rubella (German measles)
  • Herpes simplex virus
  • Toxoplasmosis (an infection with the Toxoplasma gondii parasite)
  • Syphilis (a sexually transmitted disease)

Genetics may also play a role whereby a person can inherit a specific set of genes with a susceptibility to developing cataracts at some stage in life (usually associated with the absence of a recognised / diagnosed underlying medical condition). Some genetic conditions can also make an individual more prone to the development of cataracts. Such illnesses can include:

  • Down syndrome (a chromosome 21 disorder)
  • Wilson’s disease (the accumulation of excess copper in the body’s organs)
  • Myotonic dystrophy (progressive muscle weakness)
  • Galactosemia (a rare metabolic disorder affecting the metabolism of the sugar, galactose)
  • Homocystinuria (methionine metabolism disorder)
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