A 55 year old patient complains of decreased distance vision. However, now he does not require his near glasses for near work. The most likely cause is

C i.e. Nuclear sclerosis 'Second sight' or myopic shift due to a change in refractive index of the nucleus causing index myopia, improving near vision is a feature of Nuclear Cataract/SclerosisQ. Difference Difference between immature and mature cataract Features Immature Mature Vision CF or above Usually HM Iris shadow Present Absent Purkinje's fouh image Present Absent Difference between senile immature nuclear cataract and immature coical cataract Features Senile immature nuclear Senile immature cataract coical cataract Vision - Poor in day time, may - Poor in night improve with minus lenses. time, may - Distant vision deteriorates improve with due to progressive index myopia. plus lenses - Due to nuclear sclerosis, there is improvement in near vision k/a second sight. Age of onset - Usually stas in foies - Usually stas in fifties Lens opacities - Site - Central - Peripheral - Shape - Nearly round or oval - Wedge-shaped - Colour - Brown or black spokes - Maturity - Takes long time to become - Usually white mature - Matures relatively early - Hypermaturity - Rarely becomes hypermature - If unattended, reaches hypermaturity