Antifogging and -reflection coatings were fabricated on glass and poly(methyl methacrylate) (PMMA) substrates by integrating solid silica nanoparticles of 25 nm (S-25) and mesoporous silica nanoparticles (MSNs) of 45 nm via layer-by-layer assembly without any post-treatments. Superhydrophilicity and a maximum transmittance of 98.5% in the visible spectral range was achieved for the (PDDA/S-25)4/(PDDA/MSNs) coating deposited on slide glass. The maximum transmittance even reached as high as 99.3% in the visible spectral range by applying a coating of (PDDA/S-25)8/(PDDA/MSNs) on PMMA substrate. Scanning and transmission electron microscopy were used to observe the morphology and structure of nanoparticles and coating surfaces. Optical properties were characterized by UV-visible spectrophotometer. Surface wettability was studied by a contact angle/interface system. The influence of mesopores was also discussed on the transmission and wetting properties of coatings. The high porosity of mesoporous nanoparticles and loose stacking of solid and mesoporous nanoparticles are considered to significantly contribute to the enhancements of both light transmission and hydrophilicity.