The properties of Si and Ge nanocrystals with uniformly strained Si-Si and Ge-Ge bonds have been studied. The strained Si and Ge nanocrystals were produced by the implantation of Ge+ or Si+ ions in thermally grown SiO2 films subsequently annealed under hydrostatic pressure ranging from 1 bar to 12 kbar. Correlation between the formation of the hydrostatically strained nanocrystals and the features of the photoluminescence spectra has been observed. The obtained results are discussed in terms of broadening energy gap between the levels of electron states of the hydrostatically strained nanocrystals. This effect brings about direct radiative recombination.