1. Nuclear Cataract:
Nuclear Cataracts are the most common. These are frequently related to aging. The appearance ranges from a faint haze in the pupil to a deep burnished yellow, similar to a smoky fog. As a result, the individual reports a “yellowing” of vision. Frequently, there is a shift in glasses prescription to become less hyperopic (“far sighted”) or more myopic (“near sighted”).
2. Posterior Subcapsular Cataract:
Posterior Subcapsular cataracts appear in the center of the lens of the eye. Most frequently, they occur on the posterior (back) part of the lens. There is not any usual shift in lens prescription such as is found in nuclear cataracts. Because they appear more in the center of the lens, if the pupil is small, such as in bright light, the vision is reduced. In contrast, in reduced light, such as at night, the pupil is open, allowing light to go around the cataract. As such, vision at night may be better. Or, the individual may feel driving at night is easier than sunny days. This type of cataract can also be related to a systemic disease or prolonged steroid use.
3. Cortical Cataract:
The appearance of cortical cataracts show up as “spokes of a wheel”. The opacity tends to be most pronounced in the periphery of the pupil. This means that in bright daylight and normal room lighting, the vision is not as affected as when the pupil is more dilated at night.
4. Morganian (Mature) Cataract:
The Mature Cataract is diffusely opaque or white. When the nucleus of the lens has turned yellow, and has fallen by gravity to the lower part of the lens, it is said to be a “Morganian Cataract”. Cataract surgery is highly recommended when this type of cataract develops due to the fact that damage will ultimately occur to the inside of the eye. Secondary Glaucoma is a frequent complication.
5. Congenital Cataracts:
In congenital cataracts the lens opacity is present at birth. These type cataracts can be caused from genetic or maternal reasons. There are many different morphological shapes. In infants, congenital cataracts are usually bilateral and recognized by the appearance of a white pupil, which is detected during a routine eye examination in the baby’s first six months of life. Maternal reasons for the development of cataracts may include: syphilis, rubella or secondary to amniocentesis. There are various types of congenital cataracts. The specific treatment depends on the type and severity.
6. Infantile or Juvenile Cataracts:
Infantile or Juvenile Onset cataracts have a definite genetic origin and tend to co-exist with other abnormalities such as inborn errors of metabolism, identified chromosomal abnormalities, and other eye conditions. Causes for these type of cataracts include: diabetes, galactosemia, hyperlysinemia, homocystinuria, Down Syndrome, Turners Syndrome, Muscular Dystrophy, Idiopathic Hypoparathyroidism, Rieger’s anomaly, aniridia and retinitis pigmentosa.
7. Traumatic Cataract:
Traumatic cataracts can result from two major types of injuries:
Perforating Eye Injuries: If a sharp object penetrates the eye (ex. wire) and penetrates the capsule of the lens in the eye, a cataract will frequently develop. These usually will develop at a fast rate.
Blunt Eye Injuries: If the eye is injured by a blunt compression type injury, a cataract may develop up to several years after the injury. Additionally, with this type of injury, the zonules attaching to the lens capsule may be torn or injured, which may impair the “near point” focusing ability for the individual.
8. Secondary Cataract:
A Secondary cataract, or Capsular Fibrosis, is directly related to a specific disease, systemic disorder or chemical agent such as prescription medications. For example, long term use of prednisone (steroid) frequently will result in cataracts. Many other medications have been found to cause cataracts.