In 1935, on the basis of a career of published works, Kravkov was awarded a scientific rank of Doctor of Science in Biology with the qualification in psychophysiology of the eyesight.

Kravkov was an Academic Secretary (since 1943) and Vice Chairman of the Commission on Physiological Optics at the Biological Department at the Academy of Sciences of the USSR.

On the initiative of the academician Mikhail Averbakh in 1941 an issue of a specialized periodical publication Problemy fisiologicheskoi optiki (Problems of physiological optics) was launched.

The main of them are Samonablyudeniye (Self-observation, 1922), Vnusheniye (psikhologiya i pedagogika vnusheniya) (Suggestion, its psychology and pedagogics, 1924), Ocherk psikhologii (Essay on psychology, 1925), Glaz i ego rabota (Eye and its functions, 1932), Ocherk obschey psikhofiziologii organov chuvstv (Essay on general psychophysiology of sense organs, 1946) Vzaimodeystviye organov chuvstv (Interaction of sense organs, 1948), Tsvetovoe zreniye (Colour eyesight, 1951).

In cooperation with N. Vishnevsky, Kravkov designed and constructed a special device for definition of the normality of twilight vision, that was being mass-produced for the Red Army needs during the Great Patriotic War.

It can be divided into four periods: the first one, of early creative activity (1916–1930), that took place in difficult conditions of postrevolutionary coming into being of Soviet psychology; the second one (1930–1941), mainly connected to investigations in the field of interaction of sense organs; the third one (1941–1945), chiefly directed to the solution of tasks connected with the country's defense during World War II; the fourth one (1945–1951), that coincides with the scientist's work at the Psychology Institute of the Academy of Pedagogical Science, at the State Central Helmholtz Institute of Ophthalmology, at the Psychology Sector of the Philosophy Institute of the Academy of Science of the USSR, where Kravkov kept on an extending research of the interaction of the senses organs and problems of colour eyesight.

Kravkov's wide range of scientific interests included: adaptation and interaction of the senses organs, contrast, successive images, synesthesia, bioelectricity of different levels of visual system (retina, cerebral subcortex and cortex), interaction of macular and peripheral spheres of the retina, induction of retina, electrophysiology of the eyesight (electric sensibility of the eye, lability, electroretinogram), colour eyesight and its anomalies, sensorial classical conditioning, glaucoma diagnosis methods (by colour sensation and by the reaction of a blind spot) and many other items.

Their son Yuriy Kravkov (1921–2003), Major General of Medical Service, directed the Nikolai Burdenko Main Military Clinical Hospital from 1973 to 1983.

By the order of the Minister of Health Care of the RSFSR Maria Kovrigina # 616 of November 28, 1951, the Department of Physiological Optics of the State Central Helmholtz Institute of Ophthalmology was named after Kravkov.

Nowadays the Kravkov Laboratory of Clinic Vision Physiology is one of the structural branches of the Moscow Helmholtz Scientific Research Institute of Eye Diseases.