The phrase "although at first glance" is correct and usable in written English.
It is typically used to introduce a contrast or a surprising observation that may not be immediately obvious upon initial inspection.
Example: "Although at first glance the painting seemed simple, a closer look revealed intricate details and layers of meaning."
Alternatives: "at first sight" or "initially".
Although at first glance 999 years of profits would seem far better than 65 years, those last nine centuries are really nothing to get excited about.
Although at first glance both types involve the ritual abuse of children in a context of belief in witchcraft, there the similarity ends.
They bring to mind objects from folk or religious rituals, although at first glance a viewer may not be able to determine their purpose.
Although at first glance the house seems very different from the one they found, they have remained true to the original architectural style.
Although, at first glance, the Sun's headline might have been misconstrued as a comment on Kai, it was clear from the copy that it referred to the England football team.
And although, at first glance, it might seem that Barack Obama would face a stronger impediment than would Hillary Rodham Clinton, racism may be easier to override than sexism.
Although trypophobia at first glance seems irrational, these images might be triggering a primitive threat detection system that has adaptive functionality - trypophobic images share similar spectral characteristics also found among dangerous animals.
Although surprising at first glance, many experimental results are now showing that above a given dose of contaminant, the effects observed at low dose vanish or differ qualitatively.
Although attractive at first glance, DDD do not represent the best means of either analysing the appropriateness of an antihypertensive treatment, or comparing costs between different drug classes, as a result of the drug class-specific discrepancy between PDD and DDD.
More commonly, though, the prize recognizes developments that, although unquestionably essential, at first glance defy the English language — "for their work on chirally catalysed hydrogenation reactions," in 2001; "for palladium-catalyzed cross couplings in organic synthesis," in 2010.
Although they seem at first glance to bear little relation to Turing machines, work by Dr. von Neumann later showed that at least one version of a cellular automata, in which the cells could have 29 colors, was also a universal computer.
