The first thing you can feel is a progressive loss of vision, bilateral, but the onset can be sequential in both eyes. Sometimes a fixed black spot can be seen against a bright background. Due to changes in refractive power in different parts of the lens, there can be polyopia, where multiple images of an object appear, as if one is looking into a cracked mirror, in which one can see several selves, and the mirror is cracked into several pieces, so there are several selves. Monocular diplopia with increased nearsightedness. Clinically, senile cataract is divided into three types: cortical, nuclear and subcapsular.
1.Cortical cataract Mainly characterized by gray-white clouding of the crystal cortex, its development process can be divided into four stages: incipient, immature, mature, and over-ripe stages.
2.Nuclear cataract Crystal clouding starts from embryonic nucleus and gradually expands to adult nucleus. The nucleus becomes denser and the refractive index increases, and patients often complain of reduced presbyopia or increased myopia. In the early stage, the peripheral cortex is still transparent, therefore, the pupil is dilated in the dark to improve vision, while the pupil is narrowed in bright light to reduce vision. Therefore, surgery is usually performed without waiting for complete cortical clouding.
3. Posterior subcapsular cataract Because the clouding is located in the visual axis area, it affects vision at an early stage.