Cataract is a common eye disease among the elderly, a disease in which the transparent and elastic “magnifying glass” – the lens inside the eye becomes cloudy to the extent that it is difficult to see objects in front of it due to various reasons. So, the elderly have cataract vision is not sure to decline? In fact, there are three main types of senile cataracts, which have different effects on vision: 1. Cortical cataracts The clouding of crystals usually starts from the periphery and gradually develops towards the center of the crystals, so the effect on vision is not obvious in the early stage, and it mainly manifests itself as a decrease in visual sensitivity, and the patient feels that he/she can see like there is a layer of fog, but his/her visual acuity may not be reduced in the checkup. 2. 2. Nuclear cataract The clouding of the crystals is concentrated in the center. In the early stage, due to the increase of the density of the crystals, it can cause the deepening of myopia, and the patients usually have the feeling that their vision can be improved by looking at the near places, and their vision can still be normal after wearing a certain number of myopic lenses, but with the worsening of the cloudiness in the central part of the crystals, the visual acuity can not be corrected even if they wear spectacles. 3. Posterior subcapsular cataract occurs in the center of the back surface of the crystal, once it appears, it will have more obvious effect on the vision, and it is difficult to be corrected with glasses. Doctor’s tip: In the early stage of cataract development, the clouding only occurs in one part of the lens, which may not have much effect on the patient’s vision. However, with the development of the disease, the scope of clouding in the crystal is expanding and the degree of clouding is worsening, and the vision will be gradually impaired. Therefore, cataract patients should be treated in time.