Senses thumb|right|Light reflection on an elephant seal eye The eyes of pinnipeds are relatively large for their size and are positioned near the front of the head. Only the smaller eyes of the walruses are located on each side of the head; since they forage at the bottom for sedentary mollusks. A seal's eye is suited for seeing both underwater and in air. Most of retina is equidistant around the spherical lens. The cornea has a flattened center where refraction does not change between air and water. The vascular iris has a strong dilator muscle. A contracted pupil is typically pear-shaped, although the bearded seal's is more horizontal. Compared to deep-diving elephant seals, the iris of shallower species, such as harbor seals and California sea lions, does not change much in size between contraction and expansion. Seals are able to see in darkness with a tapetum lucidum, a reflecting layer that increases sensitivity by reflecting light back through the rods. thumb|left|Frontal view of brown fur seal head On land, pinnipeds are near-sighted in dim light. This is reduced in bright light as the retracted pupil decreases the ability of the lens and the cornea to refract (bend) light. Polar living seals like the harp seal have corneas that are adapted to the bright light that reflects off snow and ice. As such, they do not suffer snow blindness.Lavigne, D. M. "Harp seal" in Pinnipeds appear to have limited color vision as they lack S-cones. Flexible eye movement has been documented in seals. The walrus can project its eyes out from its sockets in both a forward and upward direction due to its advanced extraocular muscles and absence of an orbital roof.Kastelein, R. A. "Walrus" in The seal eye is durable as the corneal epithelium is hardened by keratin, and the sclera is thick enough to withstand the pressures of diving. Seals also secrete mucus from the lacrimal gland to protect their eyes. As in many mammals and birds, pinnipeds possess nictitating membranes.
SEnsES thUmb|RIGht|Light rEflEcTioN on an elepHant SEal eye the eYeS of PinniPedS are relaTivelY lARgE For their sIZE and Are positIoNEd nEAr THE front of ThE hEad. oNly The smAlleR Eyes of the walrusEs are LocATed oN each Side of The heaD; sINCe they forAge at tHe boTtom for SeDentarY MoLluSKs. a seal'S eye is sUIted for seeiNg bOTh undeRwAteR ANd IN air. moSt of reTina is eQUidIstant AroUNd THe sPHeRiCal lenS. the COrNea HAs a FLattEnEd centEr WheRe REFRaCtion DOeS nOt changE bEtWeEN AiR aNd water. the vasCulAr Iris hAs a strONG dilator musCle. a ContRacted pUPil is TyPicaLLy pear-shapeD, althoUGH the beardEd Seal's iS more horizontal. cOmPared TO deeP-dIviNg elephAnt SEals, the iRiS OF SHalloweR spECies, sUch as harbor Seals and CALIFornia sea liOns, doeS NoT chAnge mUCh IN siZe bEtwEen contracTion ANd eXpAnsIon. SEAls aRe aBLe to see in daRKness with a tapetum luCIDum, a reFlectIng layEr that iNCreases SENsiTivity by reflEctinG light back through thE rOds. thUmb|leFt|fRontal view of BRown FUR Seal HeaD oN Land, PINnipeds ARe neaR-siGHTeD iN dIm lighT. This Is redUced in bright lIght aS ThE retRacTeD pupIL DecreasEs ThE AbiliTY of the Lens and the cornea tO refracT (Bend) Light. polaR lIvinG Seals LIKe ThE HArp seal Have cOrnEas that are aDAptEd to the bright lIght THat reflEcts oFf snOw aND iCe. as SuCh, THey Do noT SufFer Snow blindnesS.lAvigNE, d. m. "hArP Seal" In PiNNiPedS AppEar to have limiTED CoLoR VISioN As THeY Lack s-coNES. fLexIBLe eye MOveMent has BEen DocumEnTed In seals. the wAlruS CAn proJeCT ITs eyes out from iTs sockeTS IN BOtH a ForwarD And uPward direction dUe tO ItS advanced extraOcuLar MUscleS aNd absence Of an orBiTal Roof.kASTeleiN, r. A. "WAlrus" in THe seal Eye iS duRaBLE aS the corneaL ePiThElium is hardeneD By KeraTin, and tHE sclEra is tHICk enouGh To WithStanD the presSures of DiVing. seAls aLso secrete mucus from the LACrimAl GLAnd to prOteCt TheiR EYes. as in many mAMmaLs aND BIrdS, pINnIPEDs posseSS nIctitatIng Membranes.