Yes, there is such a distortion and there exist various methods to correct for it. Depending on the sub-field, it may be called nadir correction or limb correction.
One reason is the optical path length through the atmosphere. This is of major importance at wavelengths where the atmosphere is at least partly absorbing, such as in regions of the thermal infrared (outside of the 8–12 µm window region) and in most of the microwave. This is difficult to correct for in the situation of a single-channel instrument and a field of ongoing research. For example, you could check out this paper for infrared radiances:
or for microwave:
Another aspect is the actual angle of incidence on the surface. This applies at any wavelength and is related to simple geometric distortion. Additionally, in visible wavelengths (which I suppose you are mostly interested in), the incident angle of the Sun varies through the field of view of the camera. One paper on the subject is
- Leroy, M., and JL Roujean, Sun and view angle corrections on reflectances derived from NOAA/AVHRR data, IEEE Trans. Geosci. Remote Sens. 32, 684-696, 1994. doi: 10.1109/36.297985.
but there are many others.