The optical depths of the solar H Lyman &agr; and the He 584-¿ lines in interplanetary space are calculated. From these the solar line profiles at Saturn and Uranus are determined. It is found that the solar H Lyman &agr; line can be diminished strongly within a spectral region of ‖Δ&lgr;‖<0.2 ¿ from the line center. On the other hand, there is no significant absorption of the He 584-¿ line except in the downwind region where absorption occurs at Δ&lgr;~0.04 ¿. The effects of solar line modification on planetary and interplanetary glow observations are discussed.