Oxidative stress is thought to be associated with many common ophthalmic diseases.Recently studies showed that hydrogen is an antioxidant,and it can selectively reduce the hydroxyl radicals and therefore is used to the prevention and treatment of many diseases,such as retinal neovascularization disease,diabetic retinopathy,retinal ischemia-reperfusion injury,retinal light-injury,etc.Also,hydrogen has a small molecular weight and good water-and lipid-solubility,so it can diffuse freely through the cell membrane toward organelles like mitochondria to exert its treating effect.The research progresses in the application of hydrogen in ophthalmology were summarized.

Objective To determine whether the candidates who were disqualified for having phoria or tropia in People′s Liberation Army Air Force ( PLAAF) medical selection of flying cadets are qualified or not according to United States Air Force ( USAF) Medical Standards Directory , and to raise suggestions on revising PLAAF medical standards . Methods All the candidates who had participated in the final medical selection of flying cadets were reevaluated and determined as qualified or not according to USAF Medical Standards Directory .Results There was a marked difference between disqualification rates of PLAAF and USAF .13.87%of the candidates who were regerded as disqualified by PLAAF standards were qualified according to USAF Medical Standards Directory .These cadets might be eliminated by mistake . Conclusion The standard on heterophonies of the PLAAF is more stringent than that of the USAF .We shoucd revise PLAAF standards using USAF standards for reference .

The global prevalence of myopia is increasing year by year, leading to many ocular health issues and social problems. In recent years, it has been confirmed that peripheral defocus is closely related to the occurrence and development of myopia. Alteration of the state of peripheral defocus can significantly influence the progression of myopia and emmetropization, but the exact mechanisms are still unclear. At present, there is no method that can completely control myopia. Nowadays, the main controlling methods, including orthokeratology lens, peripheral defocus lens and multi-focal soft lens, have been confirmed to be closely related to peripheral defocus. In this paper, we will review and summarize the development and effect of these peripheral defocus relating control methods. In addition, the researches on the related mechanisms of peripheral retinal defocus and myopia prevention and control at home and abroad are reviewed, as well as the potential mechanisms of peripheral defocus, with a view to further improving the controlling effects of existing methods, developing new prevention and control methods and reducing the incidence and progression of myopia.