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Uncorrected refractive error in children leads to various problems in their daily life and can cause multiple problems. Objective: The current study was conducted to determine the presences of headache, eye strain and uncorrected refractive error in school going children. Methods: The study was conducted on 220 school going children of ages between 5 to 15 years. Patients with complain of headache and eye strain were included in the study after taking informed consent. All other patients with any type of squint, amblyopic, nerve palsies, or any other pathology were not included in the current study. Equipment used during the data collection include distance visual acuity chart (Snellen chart), trial box, occludes, pen torch, retinoscopy and auto refractometer. Results: Out of the total 220 participants, patients presented with complain of headache and eyestrain were 114 (51.8%) and 106(48.2%) respectively. Out of the total 220 patients, 80(36.4%) were myopic, 48(21.8%) were hyperopic and 46(20.9%) were astigmatic. Patients with no refractive error were 46(20.9%). Out of the total patients, 78(35.5%) found with mild degree of refractive error. Out of the total patients, 46(20.9%) were presented with visual acuity of 6/6. Conclusion: This study concludes that children complain of headache and eye strain can be associated with the uncorrected refractive error. Mild degrees of refractive error are more prevalent as compared to moderate and severe refractive errors. Myopia is more prevalent in school going children complaining of headache and eye strain as compared to hyperopia and astigmatism.

The new millennium has witnessed a pervasive shift of trend from AC to DC in residential sector. The shift of trend is predominantly due to independent residential solar PV systems at rooftops and escalating electronic loads with better energy saving potential integrated with diminishing prices as well as commercial availability of DC based appliances. DC has ousted AC in generation, transmission, and utilization sectors with the advent of DC based generating systems (e-g solar PV), high voltage DC (HVDC) transmission and the utilization of DC based loads respectively. However, the war of currents (AC vs DC) is still ON as regards to distribution sector. Efficiency is the parameter that once wiped DC out of the power systems scenario as compared to AC-at the time of Tesla and Edison. Therefore, the same parameter is utilized to determine which is better for distribution sector under current conditions; AC or DC? A comprehensive sensitivity analysis considering real load profile is missing in the present body of knowledge. In order to fill that gap, this paper is an attempt to include comprehensive sensitivity analysis of DC distribution system and its simulation-based comparison with AC counterpart considering real load profile. The paper uses Monte Carlo technique and probabilistic approach to add diversity in residential loads consumption and in turn to obtain instantaneous load profile. The paper also presents a futuristic perspective of power electronic converter (PEC) efficiency variation on the efficiency comparison of both AC and DC distribution systems. Since the present body of knowledge generally compares AC and DC distribution based upon assumptions and limited scenarios which results in conflicting outcomes; in contrast, the discoveries of the current examination are useful to reduce the confusions and conflictions regarding which is better at distribution scale; AC or DC?

The battle of currents between AC and DC reignited as a result of the development in the field of power electronics. The efficiency of DC distribution systems is highly dependent on the efficiency of distribution converter, which calls for optimized schemes for efficiency enhancement of distribution converters. Modular solid-state transformers play a vital role in DC Distribution Networks and Renewable Energy systems (RES).This paper deals with efficiency-based load distribution for Solid State Transformers (SSTs) in DC distribution networks. Aim is to achieve a set of minimum inputs that are consistent with output while considering constraints and efficiency. As the main feature of modularity is associated with a three-stage structure of SSTs. This modular structure has been optimized using Ant Lion Optimizer (ALO) and validated by applying it EIA (Energy Information Agency) DC Distribution Network which contains SSTs. In the DC distribution grid, modular SSTs provide promising conversion of DC power from medium voltage to lower DC range (400V). The proposed algorithm is simulated in MATLAB and also compared with two other metaheuristic algorithms. The obtained results prove that the proposed method can significantly reduce input requirements for producing the same output while satisfying the specified constraints.