His sight:
The Holy Prophet’s (Sallallahu alaihi wa sallam) sight was such that when He (Sallallahu alaihi wa sallam) saw Allah Ta’ala, neither did His eye did not blink nor cross the limits of propriety (adab).
(His) sight never swerved nor did it go wrong! Surah Najm (53:17)
The Holy Prophet (Sallallahu alaihi wa sallam) would see in all 6 directions at once-i.e. front, back, right left, above and below.
Nothing in the earth or sky is hidden from His sight. (Sallallahu alaihi wa sallam).
Hadith from Sahih Bukhari:
Translation of Hadith: It has been narrated on the authority of Hadhrat Abu Hurairah who reports that the Holy Prophet (Sallallahu alaihi wa sallam) said: Do you think that only the spot of prostration is before Me? By Allah, your Ruku and your sincerity are not hidden from Me. Certainly I see you even from behind my back.
The Holy Prophet (Sallallahu alaihi wa sallam) would see the Heaven and Hell over the skies. It has been narrated on the authority of Hadhrat Asma (May Allah be well pleased with him) that the Holy Prophet (Sallallahu alaihi wa sallam) said in His sermon:
Translation of Hadith: The Holy Prophet (Sallallahu alaihi wa sallam), “I have seen all the things of this universe from where I stood, to the extent that I have seen Heaven and hell also. (Sahih Bukhari Vol 1, Pg No: 126, Pg No: 18)
Nothing is hidden from Him
The Holy Prophet (Sallallahu alaihi wa sallam) said: Without doubt Allah SWT had placed the whole earth in front of Me and I saw its ends.” (Sahih Muslim Vol 2, Pg No: 390, Zujajatul Masabeeh, Vol 5, Pg No; 9)