This type is the most common form of age-related cataract. In this case, turbidity is created in the central part of the lens or the nucleus. In the initial stages, the lens may turn yellow or amber and the person's vision may change slightly. Sometimes patients at this stage notice that they can read better without myopic glasses, a phenomenon called "temporary improvement of near vision" or "false myopia". Over time, the nucleus of the lens becomes browner and blurring of vision increases. Night vision is reduced and it becomes more difficult to distinguish colors. Usually, both eyes are involved, but the severity may be different.

Cortical Cataract

In this type, changes are first made in the outer layers of the lens or its cortex. Opacities usually appear as white streaks or stripes extending from the edges of the lens toward the center. Patients at this stage often complain of glare and seeing light halos, especially when driving at night. One of the important features of cortical cataract is that the blurring of vision increases in high light conditions. Factors such as long exposure to sunlight, diabetes or lack of antioxidants can play a role in its occurrence.

Posterior Subcapsular Cataract

This type usually occurs behind the lens and near the posterior capsule, that is, exactly in the path of light passing to the retina. For this reason, even small opacities can significantly reduce vision. Patients usually feel reduced vision in bright light, when reading or reading a cell phone screen. In addition, they may suffer from glare when exposed to direct light. Subcapsular cataracts are often seen in younger people and may be related to long-term use of corticosteroids or metabolic diseases such as diabetes. According to data from the Mayo Clinic, this type progresses more quickly than other types and usually causes noticeable vision loss within a few months.

Anterior Subcapsular Cataract

In this type, opacity occurs in the front part of the lens just below the anterior capsule. Its symptoms are similar to other types, but are often associated with eye inflammation or tissue damage. This type is usually caused by eye injuries, intraocular inflammation, or the use of certain medications.

Congenital Cataract

In some cases, babies are born with cataracts or develop them in the first months of life. The cause may be genetic or caused by infections during pregnancy such as rubella, toxoplasmosis and cytomegalovirus. In these cases, prompt diagnosis and treatment is critical, as delay in treatment may lead to permanent lazy eye. A pediatrician or ophthalmologist usually checks for lens opacities during newborn examinations. If confirmed, early surgery can save the child's vision.

Traumatic Cataract

A direct hit to the eye or a penetrating injury can damage the lens structure and cause opacity. Sometimes the impact of the trauma is immediately apparent, but in some cases symptoms appear years later. This type may involve only one eye and is seen at a younger age than other types.

Secondary and Radiation Cataracts

Secondary cataracts are usually caused by underlying diseases or medication. For example, patients with diabetes or those taking steroid medications are at increased risk. Radiation cataracts are also seen in people exposed to ionizing or ultraviolet radiation, such as radiology workers or astronauts. This type usually progresses slowly, but if the contact with the radiation source continues, its intensity increases.

Cataract symptoms

Although both diseases can lead to vision loss, their nature, process and symptoms are fundamentally different. In cataracts, the cause of reduced vision is opacity of the lens, while in glaucoma, damage to the optic nerve occurs due to increased intraocular pressure.

In cataracts, vision loss is usually gradual and painless. On the other hand, in the acute type of glaucoma, the patient may experience eye pain, redness, nausea, and sudden blurring. Cataracts mostly affect the central vision, while in glaucoma, the peripheral vision is first lost and the field of vision narrows in the form of a tunnel. In the examination, the eye of a person with cataracts usually has a normal appearance, but in glaucoma, changes may be observed in the cornea, pupil, or optic nerve. Unlike cataracts, the main treatment is That surgery is to remove the cloudy lens, in glaucoma, the goal of treatment is to control eye pressure through medication or surgery to prevent further damage to the optic nerve.

Diagnosis and when to see a doctor

The subtle difference between the symptoms of cataracts and glaucoma requires that every person over 40, especially those with a family history, diabetes or long-term use of corticosteroids, have regular eye examinations. An ophthalmologist can diagnose the type of disease by using tools such as a slit lamp to view the lens, a tonometer to measure eye pressure, and a perimetry to check the field of vision.

Early diagnosis means easier treatment and prevention of irreversible damage. Cataracts in the early stages may not require surgery, but if they affect the quality of life, surgery is simple and successful. In contrast, the damage caused by glaucoma is usually irreversible, so early referral is more important.

Summary

Cataract and glaucoma are both important eye diseases that can threaten vision, but they have a fundamental difference in origin and treatment. In cataracts, the opacity of the lens causes blurred vision and can usually be corrected with surgery, while glaucoma damages the optic nerve and the goal of treatment is to prevent its progression. Knowing the symptoms of cataracts, such as gradual blurring of vision, seeing halos around lights, and color changes, can help with early detection. If you feel any change in vision or sensitivity to light, visiting an ophthalmologist is the best decision to maintain vision health.