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Occupational exposures comprise of a broad range of factors in constant and direct contact with the ocular surface. Cataract, a leading cause of visual impairment globally, has been associated with various occupational exposures. This review critically examines existing literature on the relationship between occupational exposures and cataract development. We aim to synthesize findings from studies exploring the impact of occupational factors such as ultraviolet (UV) radiation, ionizing radiation, welding fumes, polyaromatic hydrocarbons, tobacco dust, and other elements on the prevalence and incidence of cataract among exposed populations. In our review, certain exposures, such as UV radiation, demonstrated strong evidence regarding their association with cataract development, while others presented suggestive evidence. Hence, further studies are needed to better understand exposures of greatest concern, which can subsequently inform regulations pertaining to occupational exposures in work environments. [ABSTRACT FROM AUTHOR]

Dynamic principal component analysis (DPCA), also known as frequency domain principal component analysis, has been developed by Brillinger [Time Series: Data Analysis and Theory, Vol. 36, SIAM, 1981] to decompose multivariate time-series data into a few principal component series. A primary advantage of DPCA is its capability of extracting essential components from the data by reflecting the serial dependence of them. It is also used to estimate the common component in a dynamic factor model, which is frequently used in econometrics. However, its beneficial property cannot be utilized when missing values are present, which should not be simply ignored when estimating the spectral density matrix in the DPCA procedure. Based on a novel combination of conventional DPCA and self-consistency concept, we propose a DPCA method when missing values are present. We demonstrate the advantage of the proposed method over some existing imputation methods through the Monte Carlo experiments and real data analysis. [ABSTRACT FROM AUTHOR]